Exam 1 Content (pt 2) Flashcards
(176 cards)
1
Q
Cell Theory
A
- all organisms are made of cells
- cell is the fundamental unit of life
- cells come from preexisting ones (through cell division)
2
Q
all cells have cell membranes, cytoplasm, ribosomes, and DNA
A
true
3
Q
why does transcription occur in the cytoplasm in a prokaryote?
A
it does not have a nucleus
4
Q
what are the types of lipid structures?
A
- micelle lipid molecules
- bilayers
- liposomes
5
Q
what are the factors affect membrane fluidity?
A
- temperature
- number of cholesterols
- saturation level of fatty acids
6
Q
low temperatures cause decreased membrane fluidity while high temperatures cause increased fluidity
A
true
7
Q
why do saturated fatty acids lead to low fluidity?
A
they are stacked closely together
8
Q
longer fatty acid chains lead to less fluidity
A
true
9
Q
how are phospholipids shaped?
A
they are kinked
10
Q
what are the integral membrane proteins embedded in a membrane?
A
- transporters
- receptors
- enzymes
- anchors
11
Q
definition
diffusion
A
net movement of a solute from an area of high to low concentration through a permeable membrane
12
Q
types of:
transport processes
A
- passive
- active
13
Q
what are the types of passive transport?
A
- diffusion
- facilitated diffusion
- osmosis
14
Q
why does primary active transport use ATP?
A
to move ions against their concentration gradient
15
Q
what are the atoms involved in primary active transport?
A
- sodium
- potassium
16
Q
how does secondary active transport occur?
A
an electrochemical gradient’s potential energy is used
17
Q
what type of atom is involved with secondary active transport?
A
Hydrogen (protons)
18
Q
what is the purpose of actively transporting ions?
A
- maintain intracellular tonicity
- avoid swelling & shrinking of cells
19
Q
purpose
contractile vacuoles
A
take up excess water from inside the cell
20
Q
why do plant cells have vacuoles?
A
they provide structural integrity from the water they absorb from the environment
21
Q
purpose
chloroplast
A
convert light to sugars
22
Q
what is the plant cell wall made of?
A
polysaccharides
23
Q
purpose
endoplasmic reticulum
only in animal cells
A
synthesizes protein and lipids
24
Q
definition
turgor expansion
A
the ability of a cell wall to resist expansion when water enters the cell
25
why do animal cells burst when placed in a *hypotonic* solution?
the cells swell overtly from the excess fluid
26
what type of proteins does the ***rough endoplasmic reticulum*** synthesize?
* transmembrane proteins
* organelle proteins
* secreted proteins
27
what does the ***smooth endoplasmic reticlum*** synthesize?
phospholipids *(fatty acids)*
28
how do ***vesicles*** provide short-lived connection within the cell?
vesicles bud off an organelle, fuse with another vesicle, then unload its contents
29
# definition
**exocytosis**
releases vesicle contents to the outside
30
# definition
**endocytosis**
the process of taking material from the outside of the cell & moves it inside
31
where does ***transcription*** occur in a *prokaryote*?
cytoplasm
32
the ***nucleus*** is the site of *transcription* for a *eukaryote*
true
33
what is the difference between ***integral*** and ***peripheral*** *membrane proteins*?
* ***integrals*** are embedded in the membrane
* ***peripherals*** are only *temporarily* associated with the membrane
34
examples of ***intergal membrane proteins***
* transporters
* receptors
* enzymes
* anchors
35
# purpose
***peripheral membrane proteins***
| (2)
* ***chaperone*** other proteins through membranes
* ***promote communication***
36
# definition
**lumen**
the interior space of the *endoplasmic reticulum*
37
the *nuclear envelope* consists of an inner & outer membrane
true
38
the *nuclear envelope* is perforated with **nuclear pores**
true
39
# purpose
**nuclear pores**
allow molecules to move in & out of nucleus
40
# description
**nuclear localization signals**
short peptides that mediate protein transport *from cytoplasm*, ***into the nucleus***
41
# description
**nuclear export signals**
short peptide *with 4 hydrophobic residues* that allow for export ***from nucleus***, out through the nuclear pores
42
# purpose
**Golgi apparatus**
* modifies and sort *proteins* & *lipids* from ER
* becomes a site for CHO to attach to those *proteins* & *lipids*
43
which molecule is formed when ***CHO*** attaches to ***protein***?
glycoproteins
44
how are **glycolipids** formed?
CHO attaches to lipids in the ***Golgi apparatus***
45
what is the process called for when *CHO attaches to either _protein_ or _lipid_*
**post-translational modification**
46
# description
**lysosomes**
*specialized vesicles* that are derived from the Golgi
47
what is the purpose of ***lysosome***?
degrades damaged or arbitrary macromolecules
48
are **lysosomes** involved in *apoptosis*?
yes
49
which structures are attached to **lysosomes** that allow it to degrade substances?
***hydrolytic enymes*** that catabolize *proteins, nucleic acids, lipids, & complex CHO*
50
which organelles are not part of the ***endomembrane system***?
* mitrochondria
* chloroplasts
51
how are *mitochondria* & *chloroplasts* similar?
* both harness energy for their respective cells
* grow & multiply independently *(they have their own genomes)*
52
what are the functions of ***mitochondria*** as the site of *cellular respiration*?
oxygen is consumed by the cell, while CO2 is released
53
how does the ***mitochondria*** synthesize ATP?
it *maintains an electrochemical gradient* across its inner membrane, using this gradient to synthesize ATP
54
do plants both have *mitochondria* & *chloroplasts*?
yes
55
# purpose
**chloroplasts**
* makes simple sugars
* releases ***oxygen*** & ***water***
56
how many membranes do **chloroplasts** & **mitochondria** have?
two
57
what is the 3rd internal membrane that **chloroplasts** have called?
**thylakoid**
58
# purpose
what is the purpose of the **chlorophyll** that is contained inside the *thlakoid*?
gives the plants their green color, and absorbs light energy for it to be converted into chemical energy
59
what are the factors that affect *cell diffusion*?
* surface area
* temperature
* concentration gradient
* distance
60
why are *microfilaments* & *microtubules* dynamic?
they are able to grow & shrink inside of cells, as well as adjusting to the movements of the cell in order to maintain size & shape
61
what type protein are *microfiilaments* constructed of?
actin
62
both *MF* & *MT* have (+) and (-) ends
true
63
(-) ends assemble slower, while (+) assemble faster
true
64
what type of cell movements are ***microfilaments*** responsible for?
* contraction
* crawling
* cell division *(cytokinesis)*
* muscle contraction
65
# description
**microfilaments**
short polymers of actin that are *arranged in a helix*
66
which cell movements are **microtubules** responsible for?
* chromosome segregation
* vesicle transport
* moving materials *within* cells
67
**intermediate filaments** are very *stable*, provide support, & can *maintain cell shape*
true
68
types of **cell junctions**
* tight junctions
* adherens junctions *(desmosomes)*
* communicating junctions
69
# purpose
what do **cell junctions** connect?
* cells to cells
* cells to extracellular matrix
70
how do *MF* & *MT* lengthen and shorten?
through **polymerization** & **depolymerization**
71
# purpose
**kinesin**
carries cargo to the *cell surface*
72
# purpose
**dynein**
carries cargo to the *cell center*
73
# description
**extracellular matrix**
| (plants)
an insoluble meshwork composed of *proteins* & *polysaccharides*
74
what is the purpose of **extracellular matrix**?
* acts as a barrier
* provides support & informational cues
75
what is the **extracellular matrix** composed of?
* middle lamella
* primary cell walls
* secondary cell wall
76
what is the order in which the compositions of the **extracellular matrix** are synthesized?
1. middle lamella
2. primary cell wall
3. secondary cell wall
77
what is the purpose of **tight junctions**?
* connects the plasma membrane of adjacent cells
* forms barriers
78
what are the sides that cells with *tight junctions* have?
* apical
* basolateral
79
# definition
apical
towards the outside
80
# definition
basolateral
layer that is on the support tissue
81
**tight junctions** do not allow *paracellular leakage*
true
82
what is the purpose of **adherens junctions**?
* allows *paracellular movement* of materials
* attaches the cytoskeleton of cells
83
***desmosomes*** are a type of *adherens junctions*
true
84
what are the functions of **communicating junctions**?
allows materials to pass from cytoplasm to cytoplasm (*communicate b/t cytoplasm-cytoplasm*)
85
what are the types of **communicating junctions**?
* gap junctions
* plasmodesmata
86
where can you find ***gap junctions*** in the body?
* heart
* neurons
* retina
87
**plasmodemata** can only be found in plants
true
88
in plant cells, why are the cell membranes of two cells continuous?
they are connected by ***plasmodesmata***
89
**plasmodesmata** are responsible for passing *RNA* and *proteins* within a plant cell
true
90
where on the cell do **ECM** and **integrins** interact?
cell surface
91
what kind of information does **ECM** communicate to the cell?
the cell's *shape* and *function*
92
what is the **ECM** made of ?
* protein *(fibrous)*
* polysaccharides
93
which proteins is the **ECM** made of for *tensile strength*?
* collagen
* elastin
* laminin
94
where is the **ECM** most present?
connective tissues such as *tendons* & *ligaments*
95
which type of **collagen** is the most prevalent?
Type I
96
what type of *collagen* does the **basal lamina** have?
Type IV
97
the **basal lamina** is a *specialized ECM layer*
true
98
receptors are highly selective for the ligands they bind to
true
99
what is another term for **cell signaling**?
cell transduction
100
what are the steps in **cell signaling**?
1. *receptor activation* by ligands
2. signal *transduction* where enzymes are activated
3. *cell response*
4. *termination*
101
what are the types of **signaling receptors**?
* cell surface receptors
* intracellular receptors
102
what type of *ligand* is a **cell surface receptor** suited for?
hydrophilic (polar)
103
what type of *ligand* is a **intracellular surface receptor** suited for?
hydrophobic (nonpolar)
104
examples of **polar** *ligands*
* epinephrine
* insulin
* dopamine
105
**cell surface receptors** are a type of *integral membrane protein*
true
106
examples of **nonpolar** *ligands*
* estrogen
* testosterone
107
what are the types of **cell signaling**?
* endocrine
* autocrine
* paracrine
* juxtacrine
108
how is ***juxtacrine*** *signaling* activated?
upon contact with another cell
109
how does ***endocrine*** *signaling* occur?
ligands are secreted into the blood and travel to the site of action
110
what occurs during ***paracrine*** *signaling*?
the molecule from one cell affects a nearby cell
111
how does ***autocrine*** *signaling* occur?
a cell releases a molecule that binds to its own receptors
112
# definition
**plasmid**
circular DNA that independently replicate and contain ***genes*** of *adaptive value*
113
why are **bacterial genomes** *small*?
* allows for rapid reproduction
* allows for each daughter cell to have a copy of the genome through binary fission
114
# definition
**binary fission**
a process in which DNA duplicate & divides into two
115
# definition
**horizontal gene transfer**
the transfer of genetic material between organisms that are ***not*** *parent* & *offspring*
116
what are the methods of **horizontal gene transfer**?
* conjugation
* transformation
* transduction
117
# definition
**conjugation**
| horizontal gene transfer
DNA is transfered through cell-cell connection
118
# definition
**transformation**
| horizontal gene transfer
DNA is acquired from DNA that is *free flowing* in the environment
119
# definition
**transduction**
| horizontal gene transfer
genetic material is transfered through ***viruses***
120
transcribed mRNA is directly translated into proteins in ***bacteria***
true
121
**bacteria** are not capable of *sexual reproduction*
true
122
which features of a cell do **bacteria** lack?
* membrane-bound nuclei
* mitochondria
* intracellular compartments
123
what is the *cell wall* of ***bacteria*** made of?
peptidoglycans
124
which type of *bacteria* is the most diverse?
**proteobacteria**
125
how are ***proteobacteria*** defined?
by *similarities* in their rRNA sequences
126
what are the types of ***bacteria***?
* gram-positive
* gram-negative
127
what color do ***gram-positive*** **bacteria** stain?
blue
128
***gram-negative*** bacteria counter stain with **red**
true
129
***gram-positive*** *bacteria* have **thicker** *peptidoglycan walls* than gram-negative
true
130
there are no **archaea** that can carry-out *photosynthesis*
true
131
**archaea** are known for producting what type of gas as by-product of their energy metabolism?
**methane**
132
what are the types of ***photosynthetic bacteria***?
* monophyletic *(oxygenic)*
* polyphyletic *(anoxygenic)*
133
what makes **archaea** diverse?
horizontal gene transfer
134
**archaea** do not have any *peptidoglycan* in their cell walls
true
135
what type of environments that make **archaea** *extremophiles*?
* high salt concentrations
* high temperatures
* high acidity
136
what makes ***viruses*** not alive?
* no membranes
* no cytoplasm
* cannot harness energy
137
what does a ***virus*** need to do in order the *replicate, transcribe, & translate* their genome?
infect a host cell
138
prokaryotes *coevolved* with eukaryotes
true
139
what are the types of **genomes** that *viruses* have?
* double stranded DNA
* single stranded DNA
140
how does a cell produce ***viral proteins***?
a virus hijacks the cells's transcription & translation systems
141
how do ***viruses*** determine which host to enter?
***specificity*** dictated by *complementary proteins* on *viral* & *host* surfaces
142
why are *viruses* difficult for the immune system to fight?
they rapidly evolve & escape detection by ***memory B cells & T cells***
143
what are the *surface proteins* of ***influenza***?
* hemagglutinin
* neuraminidase
144
what is the *role* of flu's ***hemagglutinin***?
assists in entry of the virus
145
what is the *role* of flu's ***neuraminidase***?
assists in the virus's release into the body
146
# definition
**antigenic drift**
the gradual *accumulation of mutations* in genes that code for antibody-binding sites
147
# definition
**antigenic shift**
the recombination that produces novel combinations
| explains why there are different types of "flus"
148
what are the **3 conditions** for a *pandemic*?
* contain a new **H&N** *combination*
* have the ability for *replication* in humans
* efficient *transmission* between humans
149
how does **recombination** occur?
two subtypes infect the same cell
150
what is an example of **non-self**?
foreign pathogens
151
what is an example of **altered self**?
* cancer cells
* infected cells
152
how does the immune system recognize the "self" or "nonself"?
through fragments of foreign proteins displayed on the cell surface
153
how do **autoimmune diseases** develop?
the immune system misidentifies the "self" as "nonself"
154
what are the two parts of *immunity*?
* innate
* adaptive
155
# characteristics
**innate immunity**
* non-specific protection
* does not rely on previous exposure to a pathogen
156
# characteristics
**acquired immunity**
* highly selective
* requires prior exposure
157
what do **natural killer cells** target?
* cancerous cells
* host cells infected by viruses
158
how do pathogens cause disease?
* targets immune cells
* disrupts organ function
* immune system responses *(pleural effusion from PNA)*
159
what are the types of **granulocytes**?
* basophils
* eosinophils
* neutrophils
160
what are the steps to **viral replication**?
1. attachment
2. entry
3. uncoating *(of capsid)*
4. replication
5. assembly
6. release
161
what happens when a **viral capsid** is removed?
the viral genome gets released in the cell
162
what is a **viral capsid**?
a protetive protein coat around the RNA of a virus
163
what is a **viral envelope**?
a protective coating around the *viral capsid*
164
what are the *physical barriers* that are included with **innate immunity**?
* skin *(& mucus membranes)*
* fish scales
* insect exoskeletons
* tree bark
165
**innate immunity** includes *proteins* that signal infection
true
166
which type of cells release **cytokine** as a response to pathogen recognition?
* dendritic cells
* mast cells
167
what are the components of **adaptive *(humoral)* immunity**?
* B cells
* antibodies
168
which kind of cell produces ***antibodies***?
**B cells**
169
what are the types of **antibodies**?
* IgG
* IgA
* IgM
* IgE
* IgD
170
what are the cells involved with **adaptive immunity**?
* T cells
* helper T cells
* cytotoxic T cells
* regulatory T cells
171
what is the purpose of **T cells**?
secrete cytokines that activate other immune cells
172
where do **T cells** mature?
thymus
173
what is the purpose of **regulatory T cells**?
* suppress the activity of immune cells
* help suppress autoimmune diseases
174
what do **T cells** use to recognize antigens associated with *MHC proteins*?
**T cell receptors**
175
what is the difference between ***humoral*** & ***cellular*** immunity?
| both are *adaptive*
*humoral* is dependent on **antibodies**, while *cellular* depends on **cells**
176
where do ***B cells*** mature?
**bone marrow**
