AP bio midterm review Flashcards
1
Q
Metabolism
A
The totality of an organism’s chemical reactions
2
Q
Metabolic pathway
A
The series of steps in which a molecule is altered. Each step is catalyzed by an enzyme.
3
Q
Catabolic pathways
A
A type of metabolic pathway that breaks things down and releases energy.
4
Q
Anabolic pathways
A
A metabolic pathway that consumes energy to build more complicated molecules.
5
Q
Bioenergetics
A
How energy flows through living organisms.
6
Q
First law of thermodynamics
A
Energy can’t be created or destroyed, only transformed or transferred.
7
Q
Second law of thermodynamics
A
Every chemical reaction releases energy which increases entropy in the universe.
8
Q
Endergonic reactions
A
Absorbs free energy.
9
Q
Exergonic reactions
A
Releases free energy.
10
Q
Energy coupling
A
Using an exergonic process to power an endergonic one.
11
Q
ATP
A
Made of a ribose sugar, an adenine base, and three phosphate groups. It is used to make RNA.
12
Q
Conversion of ATP to ADP + Pi
A
Energy is released.
13
Q
Phosphorylated intermediate
A
A recipient molecule of a phosphate group from ATP in the process of phosphorylation.
14
Q
Regeneration of ATP
A
It can be regenerated using energy from exergonic reactions in the cell.
15
Q
Enzyme
A
A molecule that catalyzes a reaction.
16
Q
Catalyst
A
A chemical agent that speeds up the rate of reaction without being consumed.
17
Q
Activation energy
A
The amount of energy needed for the reaction to take place.
18
Q
Enzymes and activation energy
A
Enzymes reduce the required amount of activation energy.
19
Q
Active site
A
The only place on the enzyme where the substrate can attach and react.
20
Q
Catalytic cycle of an enzyme
A
The substrates attach, react, and are released. Then the enzyme is free to continue this process.
21
Q
Induced fit model
A
The tightening of the binding holding the substrates onto the enzyme, putting them in a better position for the reaction to occur faster.
22
Q
Enzyme catalysis methods
A
Providing a template for substrates, stretching substrates to break them down faster, and providing microenvironments for quicker reactions.
23
Q
Effects of temperature on enzyme activity
A
Enzyme activity increases with temperature to a point, after which high temperature denatures the enzyme.
24
Q
Cofactors and coenzymes
A
Cofactors are nonprotein helpers for catalytic activity; if they are organic, they are coenzymes.
25
Competitive inhibition
When inhibitors mimic the shape of the substrate and compete for a space on the enzyme.
26
Non-competitive inhibition
Inhibitors bind to another site on the enzyme, causing it to change shape.
27
Allosteric regulation
Occurs when a regulator attaches to one part of the enzyme and changes the way it works.
28
Feedback inhibition
Occurs when a product binds to another part of the enzyme and inhibits its own production.
29
Cell structure and enzyme control
Each organelle contains specific enzymes arranged in the order of their metabolic pathways.
30
Polar molecule
A molecule with a positive end and a negative end
31
electronegativity
the ability of an atom to attract electrons when the atom is in a compound
32
hydrogen bonds that water can form
four hydrogen bonds
33
cohesion
Attraction between molecules of the same substance
34
adhesion
An attraction between molecules of different substances
35
surface tension of water
the intermolecular hydrogen bonds between molecules of water at the surface.
36
specific heat of water
very high
37
water's moderation of temperature
high specific heat allows H2O to change less temperature when absorbs / loses heat
38
water's insulation
Ice is lighter than water, so it can float and insulate the water underneath
39
effects of heat of vaporization on living organisms
evaporative cooling and rain
40
4 degrees Celsius
water is most dense
41
Solvent
A liquid substance capable of dissolving other substances
42
solute
A substance that is dissolved in a solution.
43
Solution
A homogeneous mixture of two or more substances
44
why water is a good solvent
polarity
45
hydrophobic
Having an aversion to water; tending to coalesce and form droplets in water.
46
hydrophilic
Attracted to water
47
acid
adds hydrogen ions
48
base
reduces hydrogen ions
49
Buffer
takes and releases hydrogen ions when a solution needs it
50
bonds that a carbon atom can form
four
51
type of bonds carbon atoms form
single or double
52
Carbon skeletons vary in
length, branching, double bonds, rings
53
hydrocarbon
Compounds composed of only carbon and hydrogen
54
Hydrocarbon polarity
non-polar
55
Isomer
Compounds with the same formula but different structures.
56
structural isomers
differ in the covalent arrangements of their atoms
57
cis-trans isomers
pair of molecules are on the same or different sides of the double bond
58
enantiomers
isomers that are mirror images of each other
59
functional groups
chemical groups attached to carbon skeletons that give compounds their functionality
60
CO
carbonyl group
61
-OH
hydroxyl group
62
-COOH
carboxyl group
63
carboxyl group behaves like
acid
64
hydroxyl group polarity
polar
65
-NH2
amino group
66
amino group behaves like
base
67
-SH
sulfhydryl group
68
sulfhydral group
thiol
69
-OPO3 2-
phosphate group
70
phosphate group and water
hydrophilic
71
CH3
methyl group
72
Methyl group function
non-polar molecule that inactivates genes
73
macromolecule
A very large organic molecule composed of many smaller molecules
74
Polymer
large compound formed from combinations of many monomers
75
monomer
small chemical unit that makes up a polymer
76
dehydration synthesis
A chemical reaction where two molecules bond by removing a water molecule.
77
Hydrolysis
Breaking down complex molecules by the chemical addition of water
78
monosaccharides
simple sugars
79
Monosaccharide examples
glucose, fructose
80
Disaccharide
A double sugar, consisting of two monosaccharides joined by dehydration synthesis.
81
disaccharide examples
sucrose, lactose
82
Polysaccharides
Carbohydrates that are made up of more than two monosaccharides
83
storage polysaccharides
plants - starch, animals - glycogen
84
cellulose
structural polysaccharide component of plant cell walls.
85
Chitin
structural polysaccharide that forms exoskeleton
86
Carbohydrates
87
functional groups in carbohydrates
hydroxyl and carbonyl
88
carbon in abbreviated ring structure
carbon at each unlabeled corner
89
bond to form disaccharide
glycosidic linkage (covalent)
90
glycosidic linkage in cellulose
beta 1-4
91
Lipids and water
hydrophobic
92
Components of fat
glycerol and 3 fatty acids
93
functional groups of a fat
carboxyl and hydroxyl
94
glycerol molecules have ___ hydroxyls
three
95
bonds that connect fats
ester linkages
96
saturated fatty acid
a long-chain hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized
97
unsaturated fatty acid
A fatty acid that has one or more double bonds between carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.
98
hydrogenated fats
add hydrogen to liquid unsaturated fats to make them solid saturated fats
99
the kinks in an unsaturated fatty acid are caused by ___
cis double bonds
100
phospholipid
a lipid that contains a phosphate group instead of a third hydrocarbon
101
phospholipids form
cell membranes
102
phospholipid tails
nonpolar, hydrophobic
103
phospholipid heads
polar, hydrophilic
104
steroids
lipids characterized by a carbon skeleton consisting of four fused rings
105
cholesterol uses
Steroid hormone synthesis
106
Cholesterol dangers
processed in liver, can be bad for blood
107
disulfide bridges
covalent bonds that may further reinforce the shape of a protein
108
denaturation
loss of normal shape of a protein due to heat, pH, or other factor
109
primary protein structure
sequence of a chain of amino acids
110
secondary protein structure
occurs when hydrogen bonds link the sequence of amino acids.
111
Helices or pleated sheets
The shape of a secondary structure
112
tertiary protein structure
3D folding pattern of a protein due to side chain interactions
113
quaternary protein structure
protein consisting of more than one amino acid chain
114
peptide bond
covalent bond formed between a carboxyl and amino group in proteins
115
Dipeptide
Two amino acids bonded together
116
polypeptide
long chain of amino acids that makes proteins
117
r group
a functional group that defines a particular amino acid and gives it special properties.
118
number of r groups
20
119
groups that make up amino acids
carboxyl, amino, hydrogen, r group, and central carbon
120
Components of nucleic acids
a nitrogenous base, a five carbon sugar, and a phosphate group
121
DNA number of strands
two
122
RNA number of strands
one
123
DNA arrangement
antiparallel
124
RNA arrangement
different for different purposes
125
DNA bases
Adenine, Thymine, Guanine, Cytosine
126
RNA bases
Adenine, Uracil, Cytosine, Guanine
127
sugar-phosphate backbone
The alternating chain of sugar and phosphate to which the DNA and RNA nitrogenous bases are attached
128
Domains with prokaryotic cells
Bacteria and Archaea
129
location of DNA in prokaryotic cells
nucleoid floating in cytoplasm
130
location of DNA in eukaryotic cells
nucleus
131
endosymbiont
a cell that lives within a host cell
132
cell wall function
protection, structural support
133
plasma membrane structure
phospholipid bilayer with embedded proteins
134
plasma membrane function
selective permeability- maintains intracellular environment
135
bacterial chromosome
The DNA of a prokaryotic cell which is located in the nucleoid
136
Nucleoid
A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.
137
Cytoplasm
the region inside the cell except for the nucleus
138
Why cells are small
A cell's surface area to volume ratio limits the size of the cells because they need nutrients which come from the outside
139
surface area to volume in cells
the surface area to the volume ratio gets smaller as the cell gets larger
140
Microvilli
projections that increase the cell's surface area
141
Prokaryotic versus eukaryotic cells
Eukaryotic cells have nucleus while prokaryotic cells don't have nucleus.
142
nuclear envelope
double membrane that surrounds the nucleus
143
nuclear lamina
A netlike array of protein filaments lining the inner surface of the nuclear envelope.
144
function of the nuclear lamina
It helps maintain the shape of the nucleus.
145
Chromatin
Clusters of DNA, RNA, and proteins in the nucleus of a cell
146
chromatin forming chromosomes
form loops and coils to condense
147
Nucleolus
Found inside the nucleus and produces ribosomes and RNA
148
Ribosomes
Makes proteins
149
free ribosome location
cytosol
150
cytosol
Fluid portion of cytoplasm
151
bound ribosome location
attached to the ER
152
Free ribosome product
enzymes that catalyze sugar breakdown
153
bound ribosome product
proteins that go into membranes
154
Rough ER structure
Continuous with the nuclear envelope, separates the cisternal space inside from the cytosol on the outside.
155
function of Rough ER
Produces proteins from ribosomes, assists in protein folding, transports vesicles, and synthesizes membrane proteins and phospholipids.
156
Rough ER in protein production
It produces proteins from ribosomes and helps in their folding within the ER lumen.
157
Smooth ER structure
Membranous system of sacs and tubules; free of ribosomes
158
Smooth ER function
ER synthesizes lipids, metabolizes carbs, detoxifies poisons, stores calcium ions
159
Golgi apparatus structure
a stack of flattened membranes and associated vesicles close to the nucleus
160
Golgi apparatus function
modifies and packages proteins
161
Lysosomes
An organelle containing digestive enzymes
162
food vacuole
formed when a unicellular organism engulfs food particles or a white blood cell engulfs invaders. This is called phagocytosis
163
contractile vacuole
pumps excess water out of the cells
164
central vacuole
located in mature plant cells, contains cell sap
165
Cell Sap (Central Vacuole)
mix of inorganic ions like potassium and chloride
166
Flow of materials in cell export
ER to Golgi to Vesicle to Cell membrane
167
digestive enzymes in lysosomes
have special shapes to prevent the membrane from being digested.
168
Phagocytosis
process in which extensions of cytoplasm surround and engulf large particles and take them into the cell
169
Choloroplasts
where photosynthesis occurs. This is the conversion of sunlight into chemical energy.
170
Cytoskeleton
a network of fibers that organizes structures and activities in the cell.
171
two roles of the cytoskeleton
support and motility
172
structure of cell wall
The cell wall consists of the primary cell walls, the middle lamella, and secondary cell walls
173
endosymbiont theory
explains that eukaryotic cells may have evolved from prokaryotic cells
174
evidence for endosymbiont theory
double membrane, ribosomes, circular DNA, capable of functioning on their own
175
selective permeability
A property of a plasma membrane that allows some substances to cross more easily than others.
176
amphipathic
having both a hydrophilic region and a hydrophobic region
177
fluid mosaic model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.
178
temperature's effect on membrane fluidity
increase temp= increase fluidity
179
unsaturated hydrocarbon chains' effect on fluidity
more = longer to solidify
180
Cholesterol and fluidity
Acts as a fluidity buffer. Makes it less fluid at higher temps by restraining movement. However, makes in more fluid at lower temperatures becaus it creates space.
181
integral proteins
penetrate the hydrophobic interior of the lipid bilayer
182
peripheral proteins
bound to the surface of the membrane
183
transport proteins
allow passage of hydrophilic substances across the membrane
184
enzymatic activity
A protein built into the membrane with active site exposed to carry out important steps
185
signal transduction protein
A membrane protein with a shape that fits a chemical messenger like a hormone used to send messages
186
Cell-cell recognition proteins
Identification between cells.
187
intercellular joining proteins
membrane proteins of adjacent cells may hook together in various kinds of junctions
188
protein attachment to cytoskeleton and ECM
microfilaments non covalently bound to membrane proteins for stabilization
189
Membrane carbohydrates functions
cell recognition, anchor cells together
190
channel proteins
provide corridors that allow a specific molecule or ion to cross the membrane
191
carrier proteins
bind to molecules and change shape to shuttle them across the membrane
192
Aquaporins
water channel proteins
193
CO2 diffusion
easily pass through without help
194
Glucose diffusion
hard to get through without a carrier protein because it's polar
195
hydrogen ion transport through membrane
can't pass through by itself
196
Oxygen diffusion across bilayer
direction of concentration gradient
197
H2O diffusion across cell membrane
hard to get through by itself, usually goes through aquaporins
198
golgi apparatus
packages and processes
199
Vesicles
membrane sacs for transport in cell
200
Mitochondria
produces ATP via cellular respiration with requirement of oxygen
201
flagella/cilia
motion
202
Hypertonic
A solution with a higher concentration of solute than the cell
203
Hypotonic
A solution with a lower concentration of solute than the cell
204
Isotonic
Having the same solute concentration as the cell
205
turgid
The healthy state of plant cells where the cell is very firm and the inside of the cell is pushing against the outside. The outside of the cell is hypotonic.
206
Flaccid
Plant cell in an isotonic solution, the plant will wilt because there's not enough pressure
207
Plasmolysis
Plant cell in a hypertonic environment, the cell will lose water and the plasma membrane pulls away from the cell wall
208
Facilitated diffusion
passive transport aided by proteins
209
Active transport
Pumping a solute against its concentration gradient with the requirement of energy from the cell. This energy is usually ATP
210
sodium-potassium pump
a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell
211
membrane potential
The voltage across a cell's plasma membrane.
212
positive membrane potential
Extracellular side
213
Endocytosis
process by which a cell takes material into the cell by infolding of the cell membrane
214
Phagocytosis
A type of endocytosis in which a cell engulfs large particles or whole cells
215
Pinocytosis
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.
216
receptor-mediated endocytosis
when receptors on the outside of the cell membrane bind to specific substances outside the cell and take them in
217
Exocytosis
Process by which a cell releases large amounts of material by attaching a vesicle to the cell membrane
218
water potential
the potential energy of a volume of water, expressed as a pressure
219
Water potential's relationship to solute concentration
inversely proportional
220
How water travels
from low to high potential
221
relationship between water potential and pressure
directly proportional
222
solute potential equation
Ψs = -iCRT
223
R in solute potential equation
Pressure constant (0.0831 liter bars/mole K)
224
Relationship between solute potential and solute concentration
Higher solute concentration = lower solute potential
225
relationship between solute potential and water potential
directly proportional
226
cell size and diffusion
smaller cell - higher diffusion rate
227
redox reaction
A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.
228
oxidized reactant in cellular respiration
glucose
229
reduced reactant in cellular respiration
Oxygen
230
purpose of cellular respiration
produce ATP
231
NAD+/NADH
an organic molecule that serves as an electron carrier by being oxidized (losing electrons) to NAD+ and reduced (gaining electrons) to NADH
232
Role of NAD+ in cellular respiration
the NAD+ picks up electrons from glucose and turns to NADH to transport them
233
glycolysis location
cytoplasm
234
link reaction location
mitochondrial matrix
235
Krebs cycle location
mitochondrial matrix
236
Electron transport chain location
inner mitochondrial membrane
237
oxidative phosphorylation
powered by the redox reactions of the electron transport chain
238
substrate-level phosphorylation
The formation of ATP by directly transferring a phosphate group to ADP from an intermediate substrate
239
inputs of glycolysis
Glucose, e-, ADP, Pi, H+, NAD+, ATP 2
240
outputs of glycolysis
2 pyruvate, ATP 4, NADH, H+, H2O
241
pyruvate oxidation
Conversion of pyruvate to acetyl CoA and CO2 that occurs in the mitochondrial matrix in the presence of O2.
242
Krebs cycle inputs
2 Acetyl CoA, 6 NAD+, 2 FAD, 2 ADP
243
Krebs cycle outputs
4 CO2, 6 NADH, 2 FADH2, 2 ATP
244
Krebs cycle purpose
make electron carriers NADH and FADH2 to move on to ETC
245
amount of ATP produced per glucose during cellular respiration
30 - 32
246
Oxidation and Reduction in ETC
-NADH is oxidized (loses e-)
247
-oxygen is reduced (gains e-)
248
Use of energy from ETC
creation of ATP
249
reason for double membrane in mitochondria
Hydrogen ions stored between membranes
250
How ATP is generated in the ETC
The hydrogen ions that went into the membrane from the electron transport chain are forced to leave through an enzyme called ATP synthase which creates ATP from ADP and phosphate with the energy from the hydrogen ions leaving.
251
Why cellular respiration is completed in steps
To maximize the usage of the energy being produced
252
Step of cellular respiration where glucose is completely oxidized
2 turns of the Krebs cycle
253
Steps of cellular respiration where oxygen is needed
Pyruvate oxidation and the Krebs cycle require oxygen to be present. Oxidative phosphorylation (ETC) requires oxygen as an input
254
final electron acceptor of ETC
oxygen which then creates water
255
Protein pumps in ETC
create the H+ gradient in ETC
256
Oxygen's purpose in ETC
Very electronegative, pulls in the electrons at the end.
257
Enzyme
A protein that catalyzes chemical reactions.
258
Catalyst
A substance that speeds up a reaction without being consumed.
259
Substrate
The reactants that enzymes act upon.
260
Active Site
Region on enzyme where substrate binds.
261
Induced Fit Model
Enzyme changes shape to bind substrate better.
262
Competitive Inhibition
Inhibitor mimics substrate, blocking active site.
263
Noncompetitive Inhibition
Inhibitor binds elsewhere, changing enzyme shape.
264
Cofactors
Nonprotein helpers for enzyme activity.
265
Coenzymes
Organic cofactors that assist enzymes.
266
Energy Coupling
Using exergonic reactions to drive endergonic ones.
267
ATP
Energy carrier with three phosphate groups.
268
ADP
Adenosine diphosphate, lower energy form than ATP.
269
Substrate Level Phosphorylation
Direct transfer of phosphate to ADP from substrate.
270
Oxidative Phosphorylation
ATP production via electron transport chain reactions.
271
Glycolysis
Process breaking down glucose to pyruvate.
272
Krebs Cycle
Series of reactions producing electron carriers and CO2
273
Electron Carriers
Molecules that transport electrons in cellular respiration.
274
Fermentation
Anaerobic process converting sugars to acids or alcohol.
275
Photosynthesis
Process converting light energy into chemical energy.
276
Light Reactions
Convert solar energy into ATP and NADPH.
277
Calvin Cycle
Uses ATP and NADPH to synthesize glucose.
278
Carbon Fixation
Attachment of CO2 to RuBP in Calvin Cycle.
279
Rubisco
Enzyme catalyzing carbon fixation in photosynthesis. Most abundant enzyme on earth
280
G3P
Intermediate product in the Calvin Cycle. one is released at the end while 5 are kept in the cycle
281
Accessory Pigments
Molecules that capture additional light energy.
282
Chloroplast
Organelle where photosynthesis occurs.
283
Thylakoids
Membrane structures in chloroplasts for light reactions.
284
Stroma
Fluid in chloroplasts where Calvin Cycle occurs.
285
Absorption Spectrum
Wavelengths of light absorbed by chlorophyll.
286
pH in Thylakoid Space
Lowest due to high hydrogen ion concentration.
287
pH in Stroma
Highest due to lower hydrogen ion concentration.
288
ATP synthase
Enzyme facilitating ATP production via hydrogen ions.
289
Anthocyanins
Pigments responsible for red, purple, and blue colors in plants.
290
Xanthophylls
Yellow pigments that help in light absorption.
291
Chlorophyll breakdown
Process revealing accessory pigments during autumn.
292
Light reaction inputs and outputs
inputs - 2 H2O, 3 ADP, 3Pi, 2 NADP+; outputs - O2, 2 NADPH, 3 ATP
293
Calvin cycle inputs and outputs
inputs - 3 CO2, 9 ATP, 6 NADPH; outputs - 9 ADP, 6 NADP+, 6 H2O, 9 Pi
294
Photosynthesis Equation
6CO2 + 12H2O + light energy -> C6H12O6 + 6O2 + 6H2O
295
Oxidized Molecule in photosynthesis
Water (H2O) loses electrons during photosynthesis.
296
Reduced Molecule in photosynthesis
Carbon dioxide (CO2) gains electrons during photosynthesis.
297
Photosystem I (PSI)
Complex where light energy re-excites electrons for further transfer.
298
NADP+ in photosynthesis
Final electron acceptor in photosynthesis, forming NADPH.
299
PGA
3-carbon molecule formed during carbon fixation phase.
300
Aerobic Respiration
Oxygen-utilizing process generating maximum ATP.
301
Anaerobic Respiration
Oxygen-free process using metals as electron acceptors.
302
Oxidation and reduction in Glycolysis
glucose is oxidized and ADP is reduced
303
Exergonic Reactions
Reactions that release energy, regenerating ATP.
304
Metabolism
Totality of an organism's chemical reactions.
305
Catabolism
Energy-releasing reactions that break down molecules.
306
Anabolism
Energy-requiring reactions that synthesize molecules.
307
cytoplasmic junctions
signaling through direct contact between cytoplasms
308
direct contact signaling
touching cell surface molecules
309
Secretion of messenger molecules
signal cell releases molecules of a local regulator which are recognized by receptors on the target cell
310
synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
311
endocrine signaling
Hormones travel through the bloodstream to reach their target cells
312
transduction
how a signal moves from a releasing cell to a receptor cell
313
steps in a transduction pathway
signal reception, transduction, cellular response
314
ligand
A molecule that binds specifically to another molecule, usually a larger one.
315
G-protein coupled receptors
A special class of membrane receptors with an associated GTP binding protein; activation of a G protein-coupled receptor involves dissociation and GTP hydrolysis
316
ligand-gated ion channel
open and close when a receptor changes shape to let ions in
317
hormone transduction (transcription of genes)
Hormones go through the plasma membrane, bind to a receptor protein, enter the nucleus, and bind to specific genes
318
Intermediate steps importance in a transduction pathway
A signal caused by few signaling molecules can be greatly amplified when each molecule transmits the signals to numerous others.
319
protein kinases
transfer phosphates from ATP to protein, a process called phosphorylation
320
phosphorylation cascade
A series of different molecules in a pathway are phosphorylated in turn, each molecule adding a phosphate group to the next one in line
321
protein phosphatases
Enzymes that can rapidly remove phosphate groups from proteins.
322
second messengers
Small, non-protein, water soluble molecules or ions that send messages throughout the cells by diffusion.
323
cAMP as a second messenger
cAMP is made from ATP by adenylyl cyclase and then is turned to AMP.
324
signal amplification
Each activated molecule can activate several other molecules, creating an exponential response
325
endocrine glands
Glands of the endocrine system that release hormones into the bloodstream
326
exocrine glands
Glands that secrete substances outward through a duct
327
negative feedback
a mechanism of response in which a stimulus initiates reactions that reduce the stimulus
328
positive feedback
Feedback that tends to magnify a process or increase its output.
329
simple endocrine pathway
endocrine cells respond directly to an internal or environmental stimulus by secreting a particular hormone
330
neuroendocrine system
endocrine glands that are controlled by and interact with the nervous system
331
lipid soluble hormones
-steroid and thyroid hormones
332
-can enter cell
333
lipid insoluble hormones
large or hydrophilic and do not cross the plasma membrane but instead bind to a receptor on the cell's plasma membrane
334
Reasons for cell division
reproduction, development, renewal, and repair
335
Genome
a cell's genetic information
336
Chromosomes
the structures that contain DNA
337
Chromatin
the entire complex of DNA
338
Somatic cell
usual body cell with 46 chromosomes
339
gametes
reproductive cells with 23 chromosomes
340
sister chromatids
the two chromatids that make up the chromosome
341
centromere
the area where the sister chromatids are attached most closely
342
mitosis
division of genetic material
343
cytokinesis
division of the cytoplasm
344
Phases of the cell cycle
G1, S, G2, M
345
mitotic spindle
microtubules and associated proteins that begin to form during prophase
346
function of mitotic spindle
pulls chromatids to different sides of the cell
347
aster
short microtubules that extend from the centrosomes
348
kinetochore
section of DNA at the centromere that attaches to microtubules
349
mitotic spindle material
material from other microtubules of the cytoskeleton
350
Prophase
Microtubules form and chromosomes condense. The two centrosomes move to either side of the cell with the lengthening microtubules
351
prometaphase
The nuclear envelope breaks releasing the chromosomes and some microtubules attach to the kinetochores
352
metaphase
chromosomes line up at the metaphase plate
353
anaphase
microtubules begin to shorten pulling the chromatids away from each other
354
telophase
nuclear envelope reforms on both sides
355
Cytokinesis
cytoplasm divides
356
cytokinesis in plant cells
divide from inside out using a cell plate in middle of cell
357
cytokinesis in animal cells
cleavage furrow formed
358
binary fission
prokaryotic cells get bigger and bigger and divide.
359
Meiosis vs. Mitosis
meiosis has 2 cell divisions, mitosis only one
360
Apoptosis
programmed cell death
361
Nondisjunction
The failure of sister chromatids to separate during and after meiosis.
362
independent assortment
Independent segregation of genes during the formation of gametes
363
crossing over
Process in which homologous chromosomes exchange portions of their chromatids during meiosis.
364
high water potential to low water potential
the direction at which water flows
