Exam 4 Flashcards
(440 cards)
1
Q
A fertilized egg will form _______ that cell will divide many times and as it divides it will differentiate into different tissues.
A
zygote
2
Q
Our body after cell division and differentiation has about ____
A
200 different cell types
3
Q
What is Stem cells?
A
Stem cells stay behind they sit in the surrounding tissue that divides and differentiates and they stop dividing and sit undifferentiated unspecialized.
4
Q
_________can give rise to specialized cells once they are called to action.
A
Stem cells
5
Q
Scientist discover that some stem cells if kept in the lab can_______
A
cell divide and while others cannot, some can also differentiate into whole array of cells, and some cannot.
6
Q
What is High Genetic potential?
A
If I have a stem cell that can divide and differentiate with success for years, then I say this cell has high genetic potential
7
Q
Genetic potential of stem cells decreases with _______
A
our age
8
Q
What are the two types of stem cells?
A
Embryonic stem cells and adult stem cells
9
Q
What’s the difference between Embryonic stem cells and adult stem cells when it comes to differentiate.
A
Embryonic stem cells: can still differentiate and adult stem cells: can no longer differentiation
10
Q
Embryonic stem cells are called__________
A
pluripotent
11
Q
What can Embryonic stem cells do?
A
they can differentiate into pretty much any type of the cell in the body
12
Q
What can Adult stem cells do?
A
they can differentiate into a limited number of cells there
13
Q
Ault stem cells are called_________
A
multipotent
14
Q
What’s the process of hierarchy of stem cells?
A
First we start with the totipotent which makes the entire organism, then we have pluripotent which is an embryonic stem cell then they turn into adult stem cells to
15
Q
Stem cell will always get the _______ DNA
A
maternal
16
Q
Where are adult stem cells found?
A
most parts of the body, including brain, bone marrow, blood vessels, skin, teeth and heart
17
Q
where do we collect Embryonic stem cells?
A
Can be collected at the blastocyst where we have 100 cells
18
Q
Embryonic stem cells can be kept alive____.
A
can be kept alive indefinitely
19
Q
What is Stem cell line?
A
A replicating set of stem cells from a single blastocyst
20
Q
Embryonic stem cell are capable of ________into almost any type of cell
A
differentiating
21
Q
Why are people against on getting Embryonic stem cells?
A
we destroy the embryo
22
Q
Cancers cells have the same characteristics to ____________able to _______
A
Embryonic stem cells, divided fast
23
Q
Use for repair
A
Adult stem cells
24
Q
Caple of differentiating into cell type of the tissue in which they reside
A
Adult stem cells
25
Plasticity and survival is limited
Adult stem cells
26
Very small number of stem cells in each tissue
Adult stem cells
27
Which of the following statements correctly describes characteristics of adult cells and other cell isolated from the same tissue at the same time?
The two cell types have different patterns of DNA methylation
28
Adult cells reprogrammed by ________.
gene transfer
29
What does iPS stand for
Induced pluripotent stem cells
30
What is IPS?
skin cells were transformed into Es cells by using retroviruses to introduce extra cloned copies of four stem cells regulatory genes
31
Which of the following processes is used to convert adult cells into pluripotent stem cells (Ips).
A retrovirus is used to introduce four specific master regulatory genes
32
Making iPS cells from sick people provides a way to study the cells of those people
Including:
-Huntington's disease
-Gaucher disease
-type I juvenile diabetes
33
What are mesenchymal stem cells?
multipotent stem cells found in bone marrow that are important for making and repairing skeletal tissues, such as cartilage, bone and the fat found in bone marrow
34
Stem cell Based Therapy for the treatment of _________
Burn
35
What is Therapeutic cloning?
using stem cells to cure someone like heat, cancer
Its cloning because they are the same genetically cells only with different gene expression
36
What is Reproductive cloning?
attempting to create a new organism with is genetically identical to its parent
37
The cloning of Dolly the sheep is an example of which of the following processes?
transfer of an adult cell's nucleus into an enucleated sheep egg, followed by incubation in a surrogate
38
What are some reasons why Dolly the sheep die young.
- It could be due to the length of the telomeres as we age we lose telomeres because of DNA replication of the lagging strength
It could also be that the epigenome wasn’t wipe out
39
Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning, there is a wider divergence of opinion. Which of the following statement provides the best argument in support of therapeutic cloning?
cloning to produce embryonic stem cells may lead to great medical benefits for many
40
cancer is a genetic disease because _______________
it relates to our genetic material.
41
Cancer is not a genetic disease______
in many cases is not inherited
42
What happens in the (first mutation) ?
boost of energy happens and replace the nucleotide (first mutation) in that one cell and that cell did not die, can reproduce cellularly by mitosis
43
What happens in the second mutation?
(Second mutation) a clone from the first mutation and each of them is carrying that first mutation. The cell is still doing ok.
44
What happens in the third mutation?
(Third mutation) a patch of cells that now carry two mutations
45
What can Healthy cell
do?
-reproduce when it is told to divide and it obeys signals that are coming from two sides, opposite sides that are generated by proteins and proteins are coded by genes.
-cell goes through cell cycle
-cell division requires collaboration of multiple proteins to either promote cell division or stop cell division
46
What is proto-oncogenes (good genes)?
Those genes that promote cell division
47
What is tumor suppressor genes (good genes)?
tells the cell wait a minute it's not time to divide now
48
If everything goes ok the cell checks off _________ that are placed in the cell cycle
check points
49
How does the cell go through all the check points?
- If everything goes ok the cell checks off check points that are placed in the cell cycle
- The first set of proteins makes check one point. G1 check point is checking if the cell is good to divide, also if its time to divide
- When the cell passes the check point it will replicate its DNA and it needs repair the DNA replication. It will check point G2. When the cell is given the green light to proceed
- The cell will undergo mitosis. The nuclear material will separate into two daughter cells at the telophase when the mitotic check point happens and check if chromosomes separated, chromatid separated properly
- Cytokinesis follows
50
Stage one cancer
when the tumor is still in one location and its malignant (stage one)
51
Stage two cancer
when it grows and starts to infect nearby tissue (stage two)
52
Stange three cancer
When it grows and gets into blood lymbh vessles and can travel through the body
53
Stange fourth cancer
when cancer cells re-establish themselves in another location
54
What are the check points?
G1 to check if the cell is good to divide, is it time to divide
-G2Check point two checking if the replication was ok
-M check point to see if chromatid separated properly
55
What is cell cycle control system?
The sequential events of the cell cycle are directed
55
What is checkpoints?
where the cell cycle stops until a go-ahead signal is received
56
Cancer cells may not need ______ to grow and divide:
-make their own ______
growth factors
57
cancer cells may convey a growth factor's signal without the presence of _______
-they may have an abnormal _________
1. the growth factor
2.cell cycle control system
57
What is Transformation?
A normal cell is converted to a cancerous
58
What is a benign tumor?
if abnormal cells remain at the original site
58
What is Malignant tumor?
invade surrounding tissues and can metastasize
59
What is Metastasize?
exporting cancer cells to other parts of the body, where they can form secondary tumors
60
What is Metastasis?
The ability of these cells to spread to other sites in the body
61
a tumor is form is when
cells may reproduce at the wrong time or place
62
What is HeLa?
cells are widely used around the world in cancer labs
63
Genes that regulate cell growth and programmed cell death
1. Oncogenes-mutated proto-oncogenes
2. Tumor suppressor gene (TSGs)
Mutated genes that suppress cell divisions
3. DNA repair genes-mutated genes of DNA repair (good genes)
64
which of the following describe the role typical proto-oncogenes have when they are expressed in cells that are not cancerous?
They stimulate normal cell growth and division
65
Which of the following types of mutation would convert a proto-oncogene into an oncogene?
a mutation that greatly increases the amount of the proto-oncogene protein
66
are the receivers of the signals from the outside that would stimulate growth by stimulating cell division (grow factors)
67
What is Ras gene?
This is the gene that can be mutated and cause defective that would promote constant pushing of the cell to divide.
68
rase is for ______
oncogenes
68
Oncogenes are usually ___________
dominant
68
What is p53?
is for mutated tumor suppressor genes (cancers reflect environmental insults)
69
tumor suppressor gene are usually _____
recessive-acting mutation
70
What is which of the following describes the normal function of the P53 gene product?
It inhibits the cell cycle
71
What is Retinoblastoma?
this cancer occurs in children. Cancer of the eye
71
What is DNA repair gene
DNA repair gene
72
wont pass to generation
if the first mutation happens in the somatic tissue the cells will reproduce clonally, will have a patch of cancer cells
72
What is Polypolip?
cancer of the colon
73
wont pass to generation
if the first mutation happens in the somatic tissue the cells will reproduce clonally, will have a patch of cancer cells
74
its passed to the next generation
If the first mutation happens in the reproductive germ line. The person will have every mutation cancer cell and will be born with a predisposition to cancer
75
the somatic non inherited cancer develops after ______
age 50
76
familial cancer have an earlier onset. On average_____________ years old
10
77
What are Skin cancer types?
basal skin (should be removed)
-squamous cell (goes a little bit deeper)
-Melanoma (grows fast)
78
What is ABCDE rule
The halves wont match
B is not smooth
C different color
D for diameter
E for evolving
79
Taxol is an anticancer drug extracted from pacific yew tree. In animal cells. Taxol prevents microtube depolymerization, which interferes with which of the following processes?
Chromosome sepraration
80
What are early Detection?
PET: tumor image
Genetic testing: identify mutated genes
Screening large numbers of people: Enzyme tests markers for cancer
81
How does metastasis work?
1. Cancer cells break away from their original tissue.
2. The metastasizing cells become attached to the wall of a blood vessel or lymph vessel. They secrete digestive enzymes to create an opening. Then they cross the wall at the breach.
3. Cancer cells creep or tumble along inside the bloodstream the same way they got in. They start new tumors in new tissues.
82
Genes that promote cancer for proto-oncogene
Oncogenes
83
Genes that promote cancer for tumor suppressor gene
Muted tumor suppressor gene
84
What is the Function of the membrane
is the boundary that separates living cell form often nonliving surroundings of from extracellular space. That separate cell from its environment
85
membrane creates that boundary the border is has to allow for the cell to _____________and _________ of the multicellular organism or_____
1. uptake things that cell needs
2.release things that cell either produce for the benefit
3. the waist
85
The membrane has to be selectively permeable, allowing some substances to _______and some substances to be ____________
1. cross
2.blocked from leaving or coming in
86
What is Transmembrane proteins?
protein is inside the cell, the other side of the protein is outside of the cell
87
What is Selective permeability?
allowing some substances to cross it more easily than others
88
What is Fluid mosaic model?
states that a membrane is a fluid structure with a mosaic of various proteins embedded in it
89
What are Phospholipids?
are the most abundant lipid in the plasma membrane
90
What is amphipathic molecules?
Are phospholipids containing hydrophobic and hydrophilic regions
91
Phospholipid, two ________ and a phosphate group are attached to ______
1. fatty acids
2. glycerol
92
the two fatty acid tails are _______, but the phosphate group and its attachments from a __________
1.hydrophobic
2. hydrophilic head
93
__________ are the major component of all cell membranes
phospholipids
94
Fatty acids are __________which means that they are afraid of water
hydrophobic
95
the head is _________, which means affinity for water
hydrophilic
96
Hydrophobic, fatty acid tails are inside the _____
bilayer
96
What is Phospholipid bilayer?
is constructed in a way that hydrophilic heads are facing outside.
97
Fluid unsaturated tails ____________
prevent packing
98
Viscous
saturated tails packed together
99
cholesterol within the animal cell membrane
Cholesterol reduces membrane fluidity at moderate temperatures, but at low temperatures hinders solidification.
100
Cholesterol moderates the fluidity of the membrane by hardening in___________
colder temperatures
101
-we have fatty acids that are_________
saturated and unsaturated
102
Saturated fatty acids have the tales straight because of ________-
hydrogenation
103
Unsaturated fatty acids have those__________ therefore they can __________________
1. kinks
2.boost fluidity and permeability of the plasma membrane
104
you want to prevent rigid plasma membrane (you ______________ because ____________
1. want to keep their fluidity
2. that speaks to the plasticity)
105
If we have very rigid plasma membranes in the arteries, when we exercise and the blood flows faster, __________
the blood pressure increases the blood will be hitting the walls of the arteries and if the rigid are stiffed, they can break.
106
__________ keep the molecules from packing together
tails
107
Cholesterol reduces fluidity at moderate temperature by ______________________________It hinders solidification
reducing phospholipid movement; at low temp
108
The cholesterol promotes fluidity in _________________, reduces fluidity _________________-
1.warmer temperatures
2. in colder temperatures
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Membranes must be ________to work properly
fluid
110
As temperatures cool, membranes switch from a fluid state to a _______
solid state
111
Membranes rich in _________ fatty acids are more fluid that those rich saturated fatty acids
unsaturated
112
Phospholipids are moving __________
around all the time
113
Small, nonpolar molecules can fit in the opening between___________
Phosphate group and glycerol heads
114
Small, uncharged but polar molecules (H2O is a polar molecule) can fit into the pores between the __________
phospholipid bilayer's hydrophilic part
115
__________that do not fit in between their heads they will not be allowed to enter
Large molecules
116
_________polar molecules when they are large they will not be allowed to enter
Uncharged
117
_______________ like ions (they are not allowed)
Small but charged molecules
118
_________determine most of the membrane's specific functions
Proteins
119
Proteins are embedded in the _______
fluid matrix
120
What is Peripheral proteins?
are bound to the surface of the membrane
121
What is Integral proteins?
penetrate the hydrophobic core integral proteins that span the membrane
122
What are the Six major functions of membrane proteins
1.Transport
2.Enzymatic function
3.Signal transduction
4.Cell- cell recognition
5.Intercellular joining
6.In animal cells we have extracellular matrix
123
What is Transport?
we can have proteins that are like hallways that are channels that allow for transport.) or (we can have proteins that are related to transport, but they need to open or close to allow things in or out)
124
What is Enzymatic function?
Enzymatic function (the proteins embedded in the plasma membrane can have a specific shape that matches the substrate and they have an enzymatic function)
125
What is Signal transduction
(cells need some kind of recognition) they can have plasmas membranes that are serving as the receptor to receive the signal. Those would be involved in signal transduction pathway and they are called receptors
126
What is Cell- cell recognition?
We also have proteins that are just like antennas sticking out and they are serving self-recognition part. That antenna can be recognized by another protein in the surrounding cells and that would be the way they communicate
127
What is Intercellular joining?
Proteins can also provide a kind of junctions that are joining cells together .
128
What is extracellular ?
In animal cells we have extracellular matrix where the proteins have other molecules attached to them some kind of fibers, collagen-based and so on. That provide that attachment of one cell to another
129
What is Cells recognize?
by binding to surface molecules, often containing carbohydrates, on the extracellular surface of the plasma membrane
130
- Membrane carbohydrates may be covalently bonded to_________ forming _________ or more commonly to _______forming ______
1.to lipids
2.glycolipids
3.proteins
4.glycoproteins
131
Carbohydrates on the external side of the plasma membrane vary among _________, _________ and even ______ in an individual
species, individuals,
cell types
132
Receptors are very important in __________, but also sometimes__________, because pathogens can get into the cell if the part of the pathogen body called _______________
1. receiving signals
2. blocking pathogens
3.antigen matches the shape of the receptor, like viruses
133
How is HIV blocked into cells?
HIV can infect a cell that has CCR5 on its surface, as in most people. HIV cannot infect a cell lacking CCR5 on its surface, as in resistant individuals.
134
The plasma membrane is found inside_______
the cell
135
In _____and in the _______ apparatus so the distribution of proteins and ________, ___________ and everything is determine when the membrane is built.
ER
Golgi
Proteins
lipids
Carbohydrates
136
the membrane is built by _______ and _________apparatus. The built membrane is then in the form of __________ traveling to the __________ and they fuses with the _________
ER
Golgi
vesicles
plasma membrane
plasma membrane
137
A cell must exchange materials with its ___________, a process controlled by the _________
surroundings
plasma membrane
138
Plasma membranes are selectively _________, regulating the cell's __________
1. permeable
2.molecular traffic
139
selective permeability refers to _______
Transport
140
What is diffusion?
If I have molecules that can pass through the membrane that can pass through the membrane, a passive transport based on chemistry and physics
141
The cell might need all the other ___________that are not allows to __________. Those molecules are transported mainly by _____________.
1.molecules
2. diffuse
3.active transport
142
Transport permeability of the ___________we have to differentiate between ________ and ____________.
1. lipid bilayer
2. passive transport
3.active transport
143
Passive transport is _________is the type of _________ when the molecules can pass through the membrane because of the ______ of the openings and also the ______.
1. diffusion
2.passive transport
3.size
4.charges
144
What is Diffusion?
is the tendency of molecules to spread evenly in the available space. That refers to diffusion that can happen without a membrane being present.
145
What is an example of Diffusion?
I have perfumes and I spray them in the room even if somebody is on the other side of the room, after a while that person will smell the perfume
146
the movement of molecules is always down the ____________
concentration gradient
147
What is concentration gradient?
the difference in concentration of a substance from one area to another
148
No work must be done to move substances __________________because the molecules move by diffusion
1.down the concentration gradient
2. move by diffusion
149
the molecules from high concentration will move to the areas of _____________
lower concentration
150
when I talk about the movement of water we talk about diffusion of water called _______
osmosis
151
What is Osmosis?
is the diffusion of water across a selectively permeable membrane
152
Water diffuses across a membrane from the region of ___________ to the region of ___________
1.lower solute concentration
2.high solute concentration
153
solute will always move ___________
down the concentration gradient
154
from the lower solute concentration to the region of higher solute concentration. After a while I'll have ___________
uneven levels of solution in my two arm dish
155
when I have a low concentration of sugar solute, I have ________water molecules free to ________. When I have high concentration of sugar , that sugar ___________. I have less water molecules available here.
1. more
2.move
3.binds water
156
water will move from higher concentration of water to a __________ of water
lower concentration
157
Water also moves down the __________
concentration gradient
158
If I have concentrations of different molecules on one side higher than on the other side and if that molecule can move, it will move ______________________________________________
down the concentration gradient from high to low
159
the concentration of the solute as a reference point water will move from _________
one five molar solution
160
when I have a cell put into the environment that has the same concentration of chemicals water probably moves ________, but there is no net movement, this is an_____________
1.in and out
2. isotonic solution
161
What is Isotonic solution?
is a solution where the solute concentration is the same in the environment as it is in the solution
162
If I put a cell in the concentration higher than inside the cell water will move __________trying to________ the environment. The content of water inside the cell will______. The cell will ______.
1.out of the cell
2. dilute
3. decrease
4.shrivel
163
If I put this cell in the environment that has a lower concentration of solutes that inside the cell, then water will ___________
move into the cell.
164
-animals because they don’t have cell wall will uptake that water, uptake water (water will diffuse in, its not the will of the cell) to the point that the cell would _______, we call it ______
1.bust
2.lyses
165
If I have a plant cell, that cell will limit the diffusion of water, osmosis, by its cell wall. The plant will be normal, we say__________.
turgid
166
Isotonic solution for red blood cells is ________sodium chloride. Blood, our physiological fluids have _________ of sodium chloride
0.9%
167
low salt concentration the red blood cells will look like a _____, will have this _______ shape like a ____________
disc
donut without a hole
168
why do you feel thirst after playing in a pool for a while?
water from your body escaped you, was trying to dilute the ocean or dilute the pool.
169
What is Flaccid?
this is when the cell is losing and getting the same amount of water. It might look a little bit wilted, but is not to the point of plasmolysis
170
What is isotonic solution?
solute concentration is the same as that inside the cell; no net water movement across the plasma membrane.
171
What is Hypertonic solution?
solute concentration is greater than that inside the cell; cell loses water
172
What is hypotonic solution?
solute concentration is less than that inside the cell; call gains water
173
red blood cells and water it is not an __________because pure water is ________to red blood cells
1.isotonic solution
2.hypotonic
174
A balloon with water that water in the bucket will be________to the balloons with water inside
isotonic
175
Water transport occurs by ________. It is a passive transport and its due to physics due to the molecule's tendency to spread evenly in the given space
1. diffusion
2.pread evenly
176
What is Transport proteins?
allow passage of hydrophilic substance across the membrane
177
what is Channel proteins?
some transport proteins have a hydrophilic channel that certain molecules or ions can use as a tunnel. This will allowed water molecules inside the cell that the diffusion will allow
178
What is Aquaporins?
channel proteins facilitate the passage of water
179
what is Facilitated diffusion?
transport proteins speed the passive movement of molecules across the plasma membrane
180
What is Aquaporins?
are integral membrane proteins that serve as channels in the transfer of water, and in some cases, small solutes across the membrane
181
What is Ion channels ?
that open or close in response to a stimulus (gated channels)
182
What is diffusion?
the mechanism of transport, so it is passive
183
What does phospholipid bilayer do?
prevents large molecules or charged molecules like ions from diffusing directly across the membrane without the use of a channel protein
184
passive transport that refers to diffusion across the membrane, involves _________
membranes
185
Facilitated diffusion involves____________
proteins
186
diseases related to the malfunctioning transport
1.hypercholesterolemia
2.Cystic fibrosis
187
What is hypercholesterolemia
The lack of receptors
188
What is Cystic fibrosis?
lack of proper transport of sodium chloride outside of the cell (water accumulates in those cells. Mucus is created.
189
Active transport uses _______to move _________against their _______
1.energy
2.solutes
3.gradients
190
That active transport requires energy that is provided in the form of ______.
ATP
191
Active transport allows cells to ______________
maintain concentration gradients that differ from their surroundings
192
In animals we have sodium-potassium:
Is one type of active transport system. High concentration of sodium outside or potassium depends on what we're talking about. The will still put sodium ions outside.
193
Active transport requires ________
input energy
194
passive by diffusion and by facilitated diffusion involving _________________
proteins and active involving proteins
195
Ions they are ______, they are ________ and the cell might ________
1.small
2.charged
3.need them
196
What is Membrane potential?
is the voltage difference across a membrane
197
Voltage is created by _________
differences in the distribution of positive and negative ions
198
What is Electrochemical gradient?
two combined forces, collectively, drives the diffusion of ions across a membrane
199
A chemical force
(the ions concentration gradient)
200
An electrical force
(the effect of the membrane potential on the ion's movement)
201
electrogenic pump is a?
transport protein that generated voltage across a membrane ( 50 to 200 mV)
202
The ______________is the major electrogenic pump of animal cells
sodium-potassium pump
203
The main electrogenic pump of plants, fungi, and bacteria is a __________
proton pump
204
pumps allow for the movement of ions. This is_________
active transport
205
Large molecules are transported by ____________
cotransport
206
What is Cotransport?
Occurs when active transport of a solute indirectly drives transport of another solute
207
Plants commonly use the __________________________to drive active transport of nutrients into the cell
gradient of hydrogen ions generated by proton pumps
208
What is co-transport?
hydrogen ions will drag big molecules with them.
209
Bulk transport requires energy so its _______________. It requires building vesicles if we want to remove things this is called____________-
1.active transport
2. exocytosis
210
Vesical contains the chemicals that need to be put _________. The vesicle comes to plasma membrane, fuses with it and by that releases the content. By the same mechanism we can have an update of molecules in large amounts this is called __________
1.outside
2.Endocytosis
211
What is Endocytosis?
the cell takes in macromolecules by forming vesicles from the plasma membrane
212
Endocytosis is a reversal of _____________
exocytosis, involving different proteins
213
Food is moving by ____________are also moved into the cell by__________
1.endocytosis, antibodies
2. endocytosis
214
In animal cells what happens in isotonic
The blood cell has a balance of H2O in and H2O out and its a normal blood cell.
214
In Animal cell Hypotonic means?
Lysed happens and the blood cell over fills with H20 and burst.
215
What happens in animal cells in hypertonic
Blood Cell shriveled beacuse to much H2O out
216
In plant cells Turgid is when
Is when water stays in and its normal
217
In plant cells Flaccid is when
Water is coming in and out of the plant cell
218
In plant cells plasmolyzed is when
To much water comes out of the cell
219
The difference between stem cells and cancer cells?
Stem cells
1. Control cell cycle
2.can differentiate
3. do not adopt function
Cancer cells
1. No control of cell cycle
2. can not differentiate
3. do not adopt function
4. May spread
220
Which of the following statement correctly describes characteristics of adult stem cells and other cells isolated from the same tissue at the same time?
A. The two cell types have different patterns of DNA methylation.
B. The non-stem cells have fewer repressed genes than the adult stem cells
C. The adult stem cells have different DNA Than the non-stem cells.
D. The two Kinds of cell have virtually identical gene expression patterns in microarrays.
A
221
Which of the following processes is used to convert adult cells into pluripotent stem cells (iPS)
A. Cytoplasm from embryonic cells is injected into the adult cells
B. A retrovirus is used to introduce four specific master regulatory genes
C. The nucleus of an embryonic cell is used to replace the nucleus of an adult cell.
D. The adult stem cells are fused with embryonic cells
B
222
The cloning of Dolly the sheep is an example of which of the following processes?
A. Isolation of stem cells from a lamb embryo and production of a zygote equivalent
B. separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate sheep
C. replication and dedifferentiation of adult stem cells from sheep bone marrow
D. transfer of an adult cell's nucleus into an enucleated sheep egg, followed by incubation in a surrogate.
D
223
Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning, there is a wider divergence of opinion. Which of the following statements provides the best argument in support of therapeutic cloning?
A. A clone that lives until the blastocyst stage does not yet have human DNA
B. Cloning to produce stem cells relies on a different initial procedure than reproductive cloning.
C. Cloning to produce embryonic stem cells may lead to great medical benefits for many
D. the use of adult stem cells likely to produce more cell types than the use of embryonic stem cells.
c
224
Which of the following describes the role typical proto-oncogenes have when they are expressed in cells that are not cancerous?
A. They enhance signaling from growth factor receptors
B. they inhibit differentiation
C. they suppress tumor growth
D. They stimulate normal cell growth and division
D
225
Which of the following types of mutation would convert a proto- oncogene into an oncogene?
A. A mutation that blocks transcription of the proto- oncogene
B. a deletion of most of the proto-oncogene coding sequence
C. A mutation that greatly reduces the stability of a proto-oncogene mRNA
D. A mutation that greatly increases the amount of the proto-oncogene protein
D
226
Which of the following describes the normal function of p53 gene product?
A. It inhibits the cell cycle
B. it allows cells to pass on mutation due to DNA damage
C. It causes cells to reduce expression of genes involved in DNA repair
D. It slows down the rate of DNA replication by interfering with binding of DNA polymerase
A
227
Taxol is an anticancer drug extracted from the pacific yew tree. In animal cell, Taxol prevents microtubule depolymerization, which interferes with which of the following processes?
A. Centriole duplication
B. Chromosome condensation
C. cytokinesis
D. Chromosome separation
D
228
Which of the following statements best explains how the membranes in winter wheat are able to remain fluid in extremely cold temperatures?
A. The membranes contain an increased proportion of glycolipids.
B. The membranes contain an increased proportion of unsaturated phospholipids
C. The membranes contain a reduced proportion of cholesterol molecules
D. The membranes contain a reduced proportion of hydrophobic proteins.
B
229
Which of the following types of molecules are least likely to diffuse through the phospholipid bilayer of a cell membrane?
A. Small ions
B. small hydrophobic molecules
C. Carbon dioxide
D. Large hydrophobic molecules
A
230
Which of the following cellular processes includes all of the others?
A. osmosis
B. Transport of an ion down its electrochemical gradient
C. passive transport
D. facilitated diffusion
C
231
Celery stalks that are immersed in fresh water for several hours become stiff. Which of the following statements best explains the observation that similar stalks left in a 0.15M salt solution become limp?
A. The fresh water and the salt solution are both hypertonic to the cells of the celery stalks
B. The fresh water is hypotonic and the salt solution is hypertonic to the cells of the celery stalks
C. The fresh water is hypertonic and the salt solution is hypotonic to the cells of the celery stalks
D. The fresh water is isotonic and the salt solution is hypertonic to the cells of the celery stalks.
B
232
Look at google slide question one
233
which of the following is true of embryonic stem cells but not of adult stem cells?
A. They can differentiate into different cell types.
B. They are easy to find
C. they can continue to replicate
D. They can provide information about the process of gene regulation
E. One aim of using them is to provide cells for repair of diseased tissue
B
234
reproductive cloning of human embryos is generally considered unethical. However, about therapeutic cloning, there is a wider divergence of opinion. Which of the following statements provides a likely explanation?
A. The use of adult stem cells is likely to produce more cell types than the embryonic stem cells.
B. Cloning to produce embryonic stem cells may lead to great medical benefits for many.
C. Cloning to produce stem cells relies on a different initial procedure than reproductive cloning.
D. A clone that lives until the blastocyst stage does not yet have human DNA.
E. A clone mutates very fast
B
235
A phospholipid bilayer with equal amounts of saturated and unsaturated fatty acids displays a specific permeability to glucose. What effect will increasing the proportion of unsaturated fatty acids in the bilayer have on the membranes permeability to glucose?
A. Permeability to glucose will increase.
B. Permeability to glucose will decrease
C. Permeability to glucose will stay the same
D. Permeability will decrease initially then increase as the bilayer fills with glucose
E. Permeability will increase initially then decrease as the bilayer fills with glucose
A
236
Cells from advanced malignant tumors often have very abnormal chromosomes and an abnormal number of chromosomes. Which of the following best explains the association between malignant tumors and chromosomal abnormalities?
A. Cancer cells are no longer density- dependent
B. cancer cells are no longer anchorage-dependent
C. Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities.
D. Transformation introduces new chromosomes into cells
C
237
Which of the following statements about cancer is not true?
A. Cancer is very often associated with problems at the G1 checkpoint
B. For a tumor to be defined as cancer it must first metastasize
C. Cancer cells often have a defective form of the tumor repressor p53
D. Many cancer cells have defective form of the signal transduction protein Ras that do not become deactivated.
B
238
You have just discovered an organism that lives in extremely cold environments. Which of the following would you predict to be true about the phospholipids in its membranes, compared to phospholipids in the membranes of organisms that live in warmer environments?
A. The membrane phospholipids of cold-adapted organisms will have longer hydrocarbon tails
B. The membrane phospholipids of cold-adapted organisms will have more saturated hydrocarbon tails.
C. The membrane phospholipids of cold-adapted organisms will have more unsaturated hydrocarbon tails
D. The membrane phospholipids of cold-adapted organisms will have less unsaturated hydrocarbon tails.
c
239
Which of the following means of transport would most likely be used for moving a medium - sized molecule ( like a monosaccharide or an amino acid) from a low concentration on the outside of a cell to a high concentration on the inside of a cell?
A. facilitated diffusion through an ion channel protein
B. facilitated diffusion through a transporter
C. active transport through a pump protein
D. passive transport
c
240
What preserves the structure integrity of phospholipids bilayers?
A. peptide bonds form between the phosphate groups of the phospholipids.
B. sugars associated with the cell membrane covalently cross-link
C. hydrophobic and hydrophilic interactions between nearby phospholipids
D. Van der waals interaction between the glycerol molecule and fatty acids of a single phospholipid
C
241
What is Metabolism
is the totality of an organisms chemical reaction
242
An organism's metabolism transforms _______and _________, subject to the laws of thermodynamics
matter
energy
243
Metabolism is organized at every level of life into ___________
Metabolic pathways
244
What is Metabolic pathway?
begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
245
What is Catabolic pathway?
release energy by breaking down complex molecules into simpler compounds
246
Cellular respiration, the breakdown of _______in the presence of ______, is an example of a pathway of catabolism
glucose
oxygen
catabolism
247
What is Catabolic reaction
occur when large organic molecules are broken down into smaller, simpler ones, releasing energy in the process.
248
Smal molecules and we bring them together we invest in that reaction that requires energy. This is __________
anabolic reaction
249
What is Anabolic reaction?
involve the joining of smaller molecules into larger ones. Polymers from monomers
250
The synthesis of protein from amino acids is an example of __________
anabolism
251
What is Bioenergetic?
is the study of how organisms manage their energy resources
252
What is Energy?
is the capacity to cause change
253
Energy when we are moving is described as ___________
kinetic energy
254
When we are climbing up that’s _________
kinetic energy
255
I train my body to run a marathon and I stand on the start line I have the potential to run that marathon. So I have enough accumulated energy in my body in different forms that now I have the ability, potential to move and run the marathon. That’s an example of ___________
potential energy
256
What is Kinetic energy?
is energy associated with motion
257
What is Heat (Thermal energy)?
is kinetic energy associated with random movement of atoms or molecules
258
What is Chemical energy?
is potential energy available for release in a chemical reaction
259
Energy can be ___________ from one from to another
converted
260
_________is the energy that is capture in the chemical bond
chemical energy
261
When I break that bond, I release the energy. Before I break the bond, I have potential of doing work with that energy released from that ______________
chemical bond
262
A living organism is an open system. So we cannot have 100% of energy transformation without some losses. That loss is usually ___________
thermal energy heat
263
What is Thermodynamics
is the study of energy transformation
264
First law of thermodynamics says that ____________
energy can be transformed, but it cannot be created or destroyed
265
The second law of thermodynamic says that _____________.
every transfer of energy increases disorder.
266
The first law is also called the _____________
principle of conservation of energy
267
The second law called the __________
law of entropy
268
When I have a substrate and I break it to products, and I release energy that energy exit the molecules so that is an _________
exergonic reaction
269
if I need energy to have a reaction, I need to invest. This is endergonic when the energy goes into the product. This is an _____________
anabolic reaction.
270
What is exergonic reaction?
Proceeds with a net release of free energy and is spontaneous
271
What is Endergonic reaction?
absorbs free energy from its surrounding and is nonspontaneous
272
Exergonic reactions describes ________
catabolic reactions
273
endergonic reactions described _______
anabolic reactions
274
cells are not in equilibrium because they are ______________
open systems
275
A cell does three main kinds of work:
.Chemical
.Transport
.Mechanical
276
What is Energy coupling?
The use of an exergonic process to drive an endergonic one
277
_______--powers cellular work by coupling exergonic reactions to endergonic reactions
ATP
278
What is ATP (adenosine triphosphate)?
is the cell's energy shuttle
279
ATP is composed of ribose________, _____________, and ___________
ribose (a sugar), adenine (a nitrogenous base), three phosphate groups
280
The energy loaded molecule has three __________.
phosphate groups
281
Energy depleted molecule is adenosine diphosphate with__________.
two phosphate groups
282
Energy is carried In this chemical bond between the second and the third __________.
phosphate group
283
ATP are powered by ___________
hydrolysis of ATP
284
If I have the ATP coming to the reaction, that phosphate group is transferred to _________________ and promote synthesis. In this process, whenever we have ____________________ we have the water needed for the reaction to happen.
another molecule and activates that molecule so it can adopt another molecule
hydrolysis
285
When I have the ATP with the phosphate group from the tail is removed __________ is produced.
water
286
What is phosphorylation process?
When the third phosphate group is brought to ADP
287
APT can ______, it can deliver the _____________ to membrane to the transmembrane protein that now is activated and can ______________
transfer
phosphate group
change shape
288
Phosphorylate the motor protein that will now be activated and will move along the _________. Work in life is often done by phosphorylation of molecules. Phosphorylation activates molecules by changing its ___________. So Know it can preform the work. The same goes for transport or mechanical and for the chemical work of_________
motor protein
cytoskeletal track
shape
ATP
289
ATP goes to _________ water is needed. Energy is released
ADP
290
As I consume that dinner I would put __________________________ in my body that can broken down in my digestive system, As they are broken down in my digestive system and energy is released. ATP captures that energy and now becomes _________. After dinner you have a lot of energy, you go running. As I run the body uses the energy from food to transform it into___________ So as I run my ADP becomes _________. Its moving that phosphate group to my motor proteins so you lose ATP
Complex molecules
triphosphate
kinetic energy
ATP
291
What is Catalyst ?
is a chemical agent that speeds up a reaction without being consumed by the reaction
292
What is Enzyme?
is a catalytic protein
293
Enzyme catalysis a number of__________. They are proteins because they catalyze, they are called ___________
reactions
catalytic proteins
294
Enzymes as proteins work by _________ interactions. They have to fit the _________, so they can make the work.
key and lock
substrates perfectly
295
_____________________, that we call the active site.
The key and lock interaction is essential for the proper function of proteins. Only part of it has to match the substate
296
if the active site of the enzyme protein matches the ________________ the enzyme can preform the action
substrate by key and lock interaction
297
Enzymes do not get used up in the reaction. They can complete the reaction and then go and act on another_____________.
substate molecule
298
catalyze reactions by lowering the activation energy. Every reaction needs the_______. Catalyze lower the __________of energy needed to do the reaction
initial input
initial investment
299
The initial energy needed to start a chemical reaction is called _________, or activation energy (E A)
the free energy of activation
activation energy (E A)
300
Activation energy is often supplied in the form of __________________
heat from the surroundings
301
The reactant that an enzyme acts on is called the _____________
enzyme's substrate
302
The enzyme binds to its substrate, forming an __________________
enzyme-substate complex
303
The active site is the region on the enzyme where the _________
substrate binds
304
Enzymes are _________
proteins
305
Lets assume my protein has an active site normally does not have perfect shape for active site, but now I put a ___________ on it and that presence of the _________ creates a perfect shape of the active site.
cofactor
306
I have not perfect shape active site, But I can bind another molecule. Another molecule will bind but change the active site completely we are talking about_______________
allosteric regulation.
307
When we have a cofactor that allows the enzyme to get the proper shape. Without the cofactor the enzyme will not be able to have a proper shape but we can have instead of a ____________
competitive inhibitor
308
What does competitive inhibitor do
competitive inhibitor, we can have another molecule that will bind to that regulatory side and it will prevent the enzyme from getting a proper shape
309
Proteins have a 3D dimension. Enzymes can do that 3D folding only when they are in a proper environment and they are very picky about the applicable ___________, the applicable ________
temperature
PH
310
Enzymes require temperature for the optimum activity, but not all ___________
enzymes require the same temperature
311
What is Cofactors?
are nonprotein enzyme helpers are usually in organic metals
312
An organic cofactor called ____________
coenzyme
313
coenzymes include ____________
vitamins
314
What is Competitive inhibitors?
bind to the active site of an enzyme, competing with the substrate
315
What is Noncompetitive inhibitors?
bind to another part of an enzyme, causing they enzyme to change shape and making that active site less effective
316
Examples of inhibitors include _________________
toxins, poisons, pesticides, and antibiotics that includes pain killers
317
Cellular respiration is called _____________
aerobic
318
plants use _______________ for cellular respiration
photosynthesis
319
cells use chemical energy stored in organic molecules (_________) to regenerate _______, which power work
glucose
ATP
320
Organic matter is broken down into _______________ matter like _________ and __________ in the process of cellular respiration then __________ is made
inogranic
cardon dioxide
water
ATP
321
What is Cellular respiration?
Harvesting chemical Energy
322
It is called chemical energy because ____________________________________________
it is capture in ATP by binding the third phosphate group to the phosphate tail
323
What is Glucose chemical formula
C6H1+ 6O2 ------> 6CO2 + 6H2O +ATP
324
when glycolysis happens it happens in the __________ does not require __________
cytoplasm
oxygen
325
When we need oxygen that cellar respiration is called __________
aerobic
326
Glycolysis refers to breaking down ________ into _____________
six carbon molecules
2 pyruvates
327
What does ATP stand for
adenosine Triphosphate
328
What are the steps for cellular respiration?
Step 1 Glycolysis (does not require oxygen) Its consider Anaerobic. Converts sugar into a more unstable form called two pyruvate
(intermediate step) the 2 pyruvate are transported by active transport into mitochondria. In the Mitochondria pyruvate is oxidized and are converted to 2 acetly CoA. Covent carbon dioxide is released and 2 NADH are produced
Step 2. Krebs cycle (citric Acid cycle (an aerobic process) Corbon dioxide is released we produce 2ATP, 6NADH, and 2FADH2
Step 3. The electrons transport chain and chemiosmosis. It happens in the inner mitochondrial membrane. It requires oxygen. Electrons are transferred from the NADH and FADH2 to protein complexes and electron carriers. The electrons are used to generate a proton gradient as protons are pumped across to the intermembrane space. This generates an electrical and chemical gradient. The protons travel down their electrochemical gradient through a portion of the ATP synthase, to make ATP. Oxygen comes and combines with two hydrogens and you get water and last ATP
329
Glucose is broken down to make?
ATP
330
First step Glycolysis net yield form
2 pyruvate and 2ATP molecules and 2 NADH
331
What is NADH
Is a coenzyme, and it has the ability to transfer electrons, which will be very useful in making ATP
332
What is FADH2
FADH2 is also a coenzyme, like NADH, and it will also assist in transferring electrons
333
At the end how much ATP do we have?
30-32
334
Why does glycolysis happen
335
glycolysis happen in
cytoplasm
336
Glucose makes pyruvate and
2ATP and 2NADH
337
Moving to mitochondria pyruvate
Acetyl CoA
2NADH
2 CO2
338
CAC Acetyl CoA make
4CO2
2ATP
6NADH
339
Oxidative phosphorylation needs O2 to
e- makes H2O, 26-28 ATP
340
Cellular Respiration with inorganic and organic lables.
C6H12O6 + 6O2 organic = 6CO2 + 6 H2O + ATP inorganic
341
What is Photosynthesis?
is the reaction that feeds all organisms. Feeds us, feeds animals and it feeds plants.
341
Photosynthesis is driven by _______
light
342
Synthesis refers to _____________
making things
343
When we talk about photosynthesis we talk about making _______________________________________.
I have CO2 in the air and with the energy harvested from the sun, I build __________ and I build _________
organic matter from an inorganic matter
organic molecules
glucose
344
Photosynthesis is for ________ and cellular respiration is for ___________
plants, plants and animals
345
Photosynthesis Equation
6CO2 + 6H2O -----LIGHT ENERGY----> C6H12O6+ 6O2
346
What is Photosynthesis?
is the process that converts solar energy into chemical energy
347
The organisms that can photosynthesize are called _______because they use solar energy they are also called ___________. We can use them to produce alternative fuel energy like algae
autotrophs
photoautotrophs
348
What is Autotrophs?
sustain themselves without eating anything derived from other organisms
349
Autotrophs are the producers of the ________, producing organic molecules from ______and other inorganic molecules
biosphere
CO2
350
_________ are heterotrophs
Humans
351
What is Heterotrophs?
obtain their organic material from other organisms
352
Heterotrophs are the consumers of the biosphere, including _____________
decomposers
353
Almost all heterotrophs, including humans, depend on________ for food and __________
photoautotrophs and O2
354
Photosynthesis converts light energy to make organic matters, so light energy is transformed into chemical energy that is captured in the chemical bonds of molecules. That is possible by the _______________________
pigment, chlorophyll.
355
What is Chloroplasts?
The sites of photosynthesis in plants
356
Chlorophyll is in______________
chloroplast
357
Chloroplasts have a double membrane they have a jelly-like structure like mitochondria now its called ____________ and they have a stack of disks, _________.
stroma
thylakoids
358
The pigment is located in the membranes of those ___________ disks.
thylakoid
359
When you look at the cross-section of a leaf in plants you will notice that there are openings called ______. This is the mouth of the plant.
stomata
360
This is where the carbon dioxide is diffuses in and oxygen diffuses out.
Stomata
361
Stomata diffuse because there is lower concentration of ______, so CO2 from the air will go into the cell and photosynthesis produces______ so there is a higher concentration inside so oxygen diffuses out and that’s what we need for breathing
CO2 inside
oxygen
362
The site of photosynthesis are chloroplasts. But going to the largest structure. There is a part of the leaf where the cells have multiple chloroplasts that part is called the____________
mesophyll
363
_________ is an anatomical part of the leaf where the most intensive photosynthesis takes place
Mesophyll
364
A typical mesophyll cell has _________chloroplasts
30-40
365
Leaves appear green because_____________
chlorophyll reflects and transmits green light
366
What are the steps for photosynthesis?
1. capture light from the sun. The molecules are called pigments. The pigment is called chlorophyll found in the chloroplast. Pigment is inside the thylakoid. Light and water. Water is then split and Oxygen comes out and we make ATP and NADPH and all that is happening in the stroma
2. carbon dioxide and and ATP and NADPH enter the Calvin cycle. it is taken in by pores called stomata
the fix carbon dioxide and ATP and NADPH makes glucose
367
The light independent reaction is also called
Calvin cycle and dark reaction
368
light dependent reaction happens in the
stroma
369
Reduce NADP+___________
to NADPH
370
Generate ATP from _____ by photophosphorylation
ADP
371
Some are being shuttled by the electron buses, but in general , they are passed through the electron transport chain. We have______________
photosystem II and photosystem I.
372
- The first one is photosystem ___
II
373
What is Primary electron acceptor?
in the reaction center accepts an excited electron from chlorophyll a
374
Photosystem II (PS II) functions first ______________
the numbers reflect order of discovery) and is best at absorbing a wavelength of 680 nm (red)
375
The reaction-center chlorophyll a of PS II is called __________
P680
376
photosystem I (PS I) is best at absorbing a ___________
wavelength of 700 nm
377
The reaction-center chlorophyll a of PS I is called _____________
P700 (far-red)
378
Each electron falls down an electron transport chain from the primary electron acceptor of PS I to the _________
protein ferredoxin (Fd)
379
PS 1 is loading buses which is ____________
NADPH
380
Then we have CAM plants and CAM plants don’t use different location but different time. SO they would absorb ________at night when it is cooler and then they will go through the reaction with the close ___________ because they have sufficient CO2 accumulated. That would be a pineapple for example.
CO2
stomata
381
he fight-or -flight response is triggered by a signaling molecule called
epinephrine
382
We have an increase in the metabolic rate driven by ____________, adrenaline. That increases blood pressure, increases breathing and muscles are supplied with a lot of ___________ and we can perform.
adrenal glands
glucose
383
long-term stress different parts of our _________are working now. _________instead of the ___________
adrenal glands
Cortex
medulla.
384
They release ___________ that are acidifying our bodies. So now we can have increasing blood pressure, but that would be long term that is devastating the body. Our immune system breaks down, is suppressed
glucocorticoids
385
external signals are converted to responses within the cell: Microbes provide a _____________of the role of cell signaling in the evolution of life
glimpse
386
have an external system for a mating that can attract cells to each other they can ________ and ____________ material. This is observed in a number of organisms, including Bacteria.
fuse
exchange genetic
387
Bacteria builds_____ that are like cities where the metabolism of the cell inside can be different than the metabolism of cells outside, although they are genetically identical
biofilms
388
Why finish your antibiotic.
For the first few days the antibiotic affects bacteria on the surface of the bacterial community and the antibiotic can wipe them out. But inside the community, there are bacteria that were exposed to the antibiotic but didn’t get wiped out by the drug. So if they undergo mutation that mutation would be beneficial for them and we will end up with antibiotic-resistant bacteria
389
Cell to cell communication is essential for _________
multicellular organisms
390
The activities of cells, tissues, and organs in different parts of a multicellular organism are coordinated by __________
long-distance signals
Cell signaling
391
What is Signal transduction pathway?
is a series of steps by which a signal on a cell's surface is converted into a specific cellular response
392
Signal transduction pathway convert signals on a cell's surface into _____________
cellular responses
393
Animal and plant cells have ___________ that directly connect the cytoplasm of adjacent cells
cell junctions
394
In local signaling, animal cells may communicate by __________, or ___________
direct contact
cell-cell recognition
395
In plants cells we have _________ where the ________can flow
plasmodesmata
cytoplasm
396
in animal cells, we have __________ where the cytoplasm can flow. So these are local communications personal talks between two cells facilitated by __________of the body of two cells
gap junctions
direct contact
397
we can also have like a private talk between two cells. They talk to each other through __________ that is still _______________but based on the _________ recognition. Mostly ________ cells can talk like this. They can have a ___________. We can have_____________ also by release of signaling molecules
receptors
local signaling
cell to cell
animals
private conversations
local signaling
398
Animal cells communicate using __________, messenger molecules that travel only short distances
local regulators (local signaling)
399
Now we are releasing signaling molecules to the environment there is no direct contact between the __________ of this conversation.
participants
400
So we can have a cell that secretes a signal and that signal affect cell nearby that is called _______
paracrine signaling.
401
We can also have ____________ that is a specific type of signaling because it involves a _________ This happens between nerve cells, so we have mixture of electric impulses coming to the synaptic gap being transformed into a chemical signal by _________________.The presence of ____________ triggers the electric impulse in the ______________
synaptic signaling
neurotransmitter
neurotransmitter
neurotransmitter
receiving cell
402
if we use drugs that prevent absorption of the ______________ fast by the cell bringing the signal. _________________ lag behind in the class and stimulate the brain a little bit longer. We can developed tolerance to this prolong presence of __________________.
neurotransmitter
403
Animals and pants use chemicals called___________.
hormones
404
endocrine signaling-specialized animal cells release ___________, which travels via the ___________ to other cells
hormone molecules
circulatory system
405
plant growth regulators- travel in vessels or by _________
diffusion
406
long-distance signaling it is ___________in animals this is called the_____________ and animals release hormones. But plants also release hormones we called it ___________
chemical signaling
endocrine system
plant growth regulators
407
blood vessels transport hormones in animals and _____________________ if they have proper receptors, can get the signal.
receiving cells
408
In plants, the signal travels through vessels. There are special network of tubes in the plant's ________ and __________, which are responsible for the systemic distribution of plant hormones
xylem and phloem
409
when the signal arrives at the cell it has to be _______________ received by _______ sometimes that binding requires always binding requires a perfect match between the _________ and the _____. Activation of the receptor, usually by
uptaken,
receptor
signaling molecule
receptor
410
Signal transduction pathways have three elements.
Reception
transduction
Response
411
What is Reception?
A signal molecule binds to a receptor protein, causing it to change shape
412
A shape change in a receptor is often the initial transduction of the signal
413
receptors usually sitting on the plasma membrane. We can also have intracellular receptors
414
We can have communication local by direct contact or by the chemical signal
415
Direct contact can be a cell surface to the cell surface. In plants we have plasmodesmata. By touching cells in plants we have plasmodesmata in animals we have junction
416
the surface of plant cells is covert by cell walls and the surface of animal cells is covered by the extracellular matrix
417
Local signaling can involve chemicals that are released into a nearby environment and they work in plants and animals and that is called paracrine signaling
418
we can also have synaptic signaling present in animals because of the nervous system, where the electric impulse brought by the neuron is transformed into a chemical signal in the synaptic cleft in the form of neurotransmitters.
419
in general, we have two types of hormones in animals, steroid-based and protein-based
420
421
422
423
424
425
426
427
428
429
