AP Exam Review Flashcards
1
Q
What are the four levels of protein structure? (Unit 1)
A
- Primary
- Secondary
- Tertiary
- Quaternary
2
Q
Primary protein structure (Unit 1)
A
- sequence of amino acids that form the polypeptide chain
- determined by inherited genetic information
3
Q
Secondary protein structure (Unit 1)
A
- coils and folds in the polypeptide chain
- resulted from hydrogen bonds in the peptide backbone
- forms an alpha helix or a beta pleated sheet
4
Q
Tertiary protein structure (Unit 1)
A
- formed by interactions between multiple side chains
- interactions between R groups, hydrogen bonds, ionic bonds. hydrophobic interactions
- brings together helix and sheet
5
Q
Quaternary protein structure (Unit 1)
A
when there are multiple polypeptide chains
6
Q
How do you identify a carbohydrate? (Unit 1)
A
1:2:1 ratio of carbon, hydrogen and oxygen (cho)
7
Q
How do you identify a lipid? (Unit 1)
A
- long carbon skeleton
- phosphate/glycerol head
- fatty acid tail
8
Q
How do you identify a polypeptide? (Unit 1)
A
- repeating structure (amino acid chian)
- R groups
- Sulfur
- Carboxyl end and amino acid end
9
Q
How do you identify a nucleic acid? (Unit 1)
A
- made of nucleotides
- sugar and phosphate backbone with nucleotides in the middle
10
Q
What is the purpose of starch? (Unit 1)
A
- storage polysaccharide (carb) for plants
- stores extra glucose monomers in chloroplasts and other plastids
11
Q
What is the purpose of glycogen? (Unit 1)
A
- storage polysaccharide (carb) for animals
- stores extra glucose in liver/muscle cells
12
Q
What is the purpose of cellulose? (Unit 1)
A
- structural polysaccharide (carb) for plants
- strengthens the cell wall
13
Q
Which fat is solid at room temperature, saturated or unsaturated? (Unit 1)
A
Saturated fats
14
Q
What’s the difference between saturated and unsaturated fats? (Unit 1)
A
Saturated –> no double bonds, solid at room temperature, animal fats, have as many hydrogen atoms as possible
Unsaturated –> liquid at room temperature, oils, plant and fish fats, have at least one double bond
15
Q
Why do hydrogen bonds form between water molecules? (Unit 1)
A
- have polar covalent bonds
- oxygen has a slight negative charge and hydrogen has a slight positive
- oxygen is more electronegative so the electrons are closer to them
16
Q
What is a dehydration synthesis reaction? (Unit 1)
A
2 monomers bond through the loss of a water molecule, water molecule is formed and separates from the now polymer
17
Q
What is a hydrolysis reaction? (Unit 1)
A
Water is added to the polymer and splits into two monomers
18
Q
What bonds are formed in each of the four major types of macromolecules by a dehydration synthesis reaction? (Unit 1)
A
Carbohydrates –> joins monosaccharides with a covalent bond called a glycosidic linkage
Lipids –> ester bonds
Proteins –> Peptide bonds links amino acids
Nucleic acids –> phosphodiesterase linkage links sugars and phosphate groups to create the sugar-phosphate backbone
19
Q
What is the general structure of an amino acid? (Unit 1)
A
- Amino group
- Carboxyl group
- carbon skeleton between the groups
- side chain in the middle, R group
20
Q
What are the most common functions of carbohydrates? (Unit 1)
A
- stores glucose in plants and animals for later use
- structural, in plants toughens cell wall
21
Q
What are the most common functions of lipids? (Unit 1)
A
- energy storage
- store long term food reserves
- insulation
22
Q
What are the most common functions of proteins? (Unit 1)
A
- speed up chemical reactions (enzymatic)
- protect from disease (defense)
- movement (contractile/motor)
- store amino acids (storage)
- transport
- cellular communication
- structural support
- literally everything
23
Q
What are the most common functions of nucleic acids? (Unit 1)
A
- provides DNA and RNA
- tells the body how to function
- DNA self replicates
- DNA directs synthesis of mRNA
- mRNA directs production of a polypeptide (protein)
24
Q
What are the six properties of water? (Unit 1)
A
- Cohesion (attraction between same molecules)/adhesion (attraction between different molecules)
- Surface tension (due to hydrogen bonds)
- High specific heat (needs a lot of heat to change temp)
- Evaporative cooling
- Expansion upon freezing (ice floats)
- Solubility (can dissolve polar molecules)
25
What is the structure of the nucleus? (Unit 2)
- DNA is organized into chromosomes
- nuclear envelope = inner and outer membrane
- ribosomes, nuclear pores located on the membrane
26
What is the function of the nucleus? (Unit 2)
Contains the DNA in a eukaryotic cell, controls the cell's activities
27
What is the structure of the endoplasmic reticultum (ER, smooth and rough)? (Unit 2)
- smooth ER lacks ribosomes
- rough ER has a surface studded with ribosomes
- both are made up of cisternae, flattened vesicles
28
What is the function of the endoplasmic reticulum (ER, smooth and rough)? (Unit 2)
smooth ER
- detoxify, create lipids, metabolize carbs
- stores calcium ions
rough ER
- ribosomes secrete glycoproteins (proteins bonded to carbs)
- distributes transport vesicles
29
What is the structure of the golgi apparatus? (Unit 2)
flattened membranous sacs called cisternae
30
What is the function of the golgi apparatus? (Unit 2)
modifies proteins created by the ER, sorts and packages them into transport vesicles
31
What is the structure of the vesicles and vacuoles? (Unit 2)
Vesicles are secretory proteins surrounded by membranes
Vacuoles are large vesicles derived from the ER and golgi
32
What is the function of vesicles and vacuoles? (Unit 2)
Vesicles transfer proteins around the cell
Vacuoles help move things out of the cell
33
What is the structure of lysosomes? (Unit 2)
membranous sacs of hydrolytic enzymes
34
What is the function of lysosomes? (Unit 2)
digests macromolecules
35
What is the structure of the mitochondria? (Unit 2)
- double membrane
- free ribosomes
- circular DNA molecules
36
What is the function of the mitochondria? (Unit 2)
Cellular respiration, uses oxygen to make ATP
37
What is the structure of a chloroplast? (Unit 2)
- double membrane
- free ribosomes
- circular DNA molecules
38
What is the function of a chloroplast? (Unit 2)
- sites for photosynthesis
- grow and reproduce independently in cells
39
What is the function of the ribosomes (free vs bound)? (Unit 2)
Free ribosomes
- located in cytosol
- create proteins that stay in the cytosol
Bound ribosomes
- located on the outside of the ER
- create proteins that will be exported out of the cell or will become part of the plasma membrane
40
What is the endosymbiotic theory and what evidence supports it? (Unit 2)
- free aerobic prokaryote engulfed an anaerobic cell through endocytosis. The engulfed cell did not get digested and instead the arrangement became mutually beneficial. Over time the engulfed cell lost functionality and became the mitochondria of the eukaryotic cell.
- They both create energy from stored material
- contain their own DNA in ribosomes
- Double membranes
41
What's the difference between passive transport and active transport? (Unit 2)
Passive transport doesn't use energy and more solutes along their concentration gradients. It's spontaneous and random. (Diffusion/Facilitated diffusion)
Active transport requires energy in order to more solutes against their gradients.
42
What are the parts of a cell membrane? (Unit 2)
- lipid bilayer (amphipathic phospholipids)
- proteins, aren't randomly distributed, floating in the bilayer
- carbohydrates on the surface
- cholesterol in the bilayer
43
Where are the proteins in the cell membrane? (Includes types of proteins) (Unit 2)
Clustered in groups, determine the membrane's function
- peripheral proteins, on the surface
- integral proteins, penetrate the hydrophobic core
- transmembrane proteins, Integral proteins that down the membrane
44
What are the functions of proteins on the cell membranes? (Unit 2)
Cell to cell recognition, intercellular joining, transport, structure, enzymatic activity, signal transduction
45
What is the function of carbohydrates on the cell membrane? (Unit 2)
Cell to cell recognition, bind with molecules
46
What is the function of the cholesterol in the lipid bilayer? (Unit 2)
Is located within the bilayer.
- at high temps it restrains the movement of the lipids
- at low temps it maintains fluidity by preventing tight packing
47
How does temperature affect the fluidity of a cell membrane? (Unit 2)
As temperature decreased membranes switch from a fluid to a solid state. Membranes with more unsaturated fats are less tightly packed and more fluid.
A cell membrane must be fluid to proper function.
48
What are the 3 types of tonicity and where does water move for each? (Unit 2)
Isotonic - concentration inside is equal to outside the cell, no net water movement
Hypertonic - solute concentration is greater outside the cell, cell loses water
Hypotonic - solute concentration is greater inside the cell, cell gains water
49
What are the types of bulk transport? (Unit 2)
Exocytosis and Endocytosis
50
What is bulk transport? (Unit 2)
A type of transport that uses energy to move polysaccharides and proteins and other large molecules across the membrane through the use of vesicles.
51
What is exocytosis? (Unit 2)
- releases molecules out of cell
- vesicles fuse with the membrane and release their contents
52
What is endocytosis? (Unit 2)
The cell takes in macromolecules by forming vesicles from the plasma membrane
53
What do all cells have in common? (Unit 2)
- plasma membrane
- cytoplasm, jelly like region within the cell
- DNA, genetic material of the cell
- ribosomes, which synthesize proteins
54
What is the difference between plant and animal cells? (Unit 2)
- plants have cell walls to provide structure, animal cells only have a cell membrane
- plant cells have chloroplasts
- animal cells have mitochondria
55
Pathway of a protein produced by bound ribosomes on rough ER (Unit 2)
Rough ER --> creates the protein
vesicles --> takes it to the golgi
golgi --> modifies the protein
vesicles --> takes them out or in the cell
Together they synthesize and isolate proteins for use within or outside the cell
56
What is the difference between prokaryotic and eukaryotic cells? (Unit 2)
- eukaryotic has a nucleus, prokaryotic has a nucleoid, DNA is stored in these two locations
- prokaryotic cells have membrane-bound organelles
57
What happens during reception? (cell signaling) (Unit 4)
- Receptors on or in the cell bind to a ligand/signaling molecule
- causes change in shape of the receptor
- this is the initial transduction of the signal
58
What happens during transduction? (cell signaling) (Unit 4)
- cascades of molecular interactions
- signals are transmitted from receptors to relay molecules
59
What happens during response? (cell signaling) (Unit 4)
- response occurs in nucleus or cytoplasm
- may turn off or on genes (regulates protein synthesis)
- Other responses include cell division
60
What are the two types of signaling and how are they different? (Unit 4)
Paracrine signaling
- short distance
- cells are touching
Endocrine signaling
- long distance
- uses hormones which travel via the circulatory system
61
What does a hydrophilic ligand do? (Unit 4)
- bind to receptors on the plasma membrane, on the cell surface
- cannot diffuse through the membrane
62
What does a hydrophobic ligand do? (Unit 4)
- can diffuse through the plasma membrane
- bind to internal receptors
63
What are G-protein coupled receptors? (Unit 4)
- transmembrane receptor
- works with the help of a G protein
- G proteins bind GTP
64
What are tyrosine kinase receptors? (Unit 4)
- membrane receptors
- catalyze transfer of phosphate groups from ATP to other proteins
- Can trigger multiple signal transduction pathways at once
65
What are ligand gated ion channels? (Unit 4)
- acts as a gate that opens and closes when a receptor changes shape
- when open, lets through ions
66
What are the steps of interphase? Describe each one. (Unit 4)
G0 - Gap Phase - cell is not preparing to divide/not dividing
G1 - Gap 1 - Cell grows
S - Synthesis - DNA replication occurs, creates two identical sister chromatids for each chromosome
G2 - Gap 2 - Cell grows
M - Mitosis
67
What are the phases of mitosis in order? (Unit 4)
Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
68
What happens during prophase? (Unit 4)
- chromosomes begin to condense
- spindle fibers emerge from the centrosomes
- nuclear envelop breaks down
69
What happens during metaphase? (Unit 4)
- Mitotic spindle is fully developed
- chromosomes are lined up at the metaphase plate (line directly between the centrosomes)
- centrosomes are at opposite poles
- each sister chromatid is attached to a spindle fiber
70
What happens during anaphase? (Unit 4)
- cohesion proteins binding chromatids break
- the now chromosomes are pulled toward opposite poles
- non-kinetochore spindle fibers lengthen, elongating the cell
71
What happens during telophase? (Unit 4)
- chromosomes begin to decondense
- mitotic spindle breaks down
- nuclear envelop material surrounds each set of chromosomes
72
What happens during cytokinesis? (Unit 4)
- The cytoplasm separates into two identical daughter cells
- Animal cells --> cleavage (cleavage furrow appears and the cell splits)
- Plant cells --> cell plate (vesicles fuse into a plate which fuses with the cell wall)
73
What do cyclins and cyclin-dependent kinases do? (Unit 4)
- drive the events of the cell cycle
- cyclin bonds to a cdk to activate it
- cdk activity rises and falls with changes in cyclin concentration
74
What is the difference between mitosis and cytokinesis? (Unit 4)
Mitosis - division of a nucleus
Cytokinesis - division of the cytoplasm at the end of mitosis
75
What is phosphorylation and dephosphorylation? (Unit 4)
Phosphorylation - addition of a phosphate group (done by a kinase)
Dephosphorylation - removal of a phosphate group (done by a phosphatase)
76
What are the similarities between mitosis and meiosis (Unit 5)
- Nuclear envelope disappears
- DNA coils into chromosomes
- Chromosomes align in the center of the cell
- Fibers separate chromosomes
nuclear envelope reappears
- Chromosomes uncoil
- Followed by cytokinesis and the production of daughter cells
77
What are the differences between mitosis and meiosis (Unit 5)
Mitosis:
- Creates 2 daughter cells
- Creates cells that are genetically identical to each other and the parent cell
- Conserves the number of chromosome sets
- Sister chromatid cohesins are cleaved at the end of metaphase
Meiosis:
- Creates 4 daughter cells
- Creates cells that are genetically varied
- Reduces the number of chromosome sets from 2 diploid to 1 haploid
- Cohesins between homologs are cleaved in anaphase 1 and between sister chromatids in anaphase 2
- Has synapsis/crossing over in prophase 1
- During metaphase 1 homologous pairs align at the metaphase plate
- During anaphase 1 homologs are separated
78
How does the movement of chromosomes during meiosis explain Mendel's Law of Segregation of alleles (Unit 5)
Law - two alleles for a given trait separate from each other giving the gametes only one allele for the trait. This way offspring inherit one allele from each parent
Meiosis - During anaphase, the chromosomes are pulled apart and separated into different gametes
79
How does the movement of chromosomes during meiosis explain Mendel's Law of Independent Assortment (Unit 5)
Law - Genes separate independently during gamete formation. The allele a gamete receives for one gene doesn't affect the allele it receives for another gene
Meiosis - During metaphase, the chromosomes randomly line up at the metaphase plate
80
What is responsible for aneuploidy (Unit 5)
The fertilization of gametes in which nondisjunction occurred
81
What is nondisjunction (Unit 5)
A pair of homologs doesn't separate normally in meiosis resulting in gametes with two of the same chromosome or none
82
What is a helicase? (Unit 6)
Enzymes that untwist the double helix at the replication forks
83
What does DNA polymerase do? (Unit 6)
Catalyze the synthesis of new DNA at the replication fork
84
What does topoisomerase do? (Unit 6)
Relieves the strain of twisting the double helix by breaking/swiveling/rejoining DNA strands
85
What does ligase do? (Unit 6)
The segments created in the lagging strand are joined together by DNA ligase
86
What does the RNA polymerase do? (Unit 6)
Pries apart the DNA strands and joins together the RNA nucleotides
87
How is transcription different in prokaryotes and eukaryotes? (Unit 6)
Prokaryotic transcription takes place in the cytoplasm while eukaryotic transcription takes place in the nucleus
88
How is translation different in prokaryotes and eukaryotes? (Unit 6)
Prokaryotes → translation can begin before transcription is finished
Eukaryotes → the nuclear envelope separates the two processes
89
What is the structure of tRNA? (Unit 6)
- Consists of a single RNA strand that twists into a 3D shape due to hydrogen bonding
- Roughly L shaped with 5’ and 3’ ends located near one end of the structure
- 3’ end is an attachment site for an amino acid
90
What does tRNA do? (Unit 6)
Enables translation of a given mRNA codon into an amino acid
91
What does rRNA do? (Unit 6)
Helps form ribosomes
92
What is methylation? (Unit 6)
The addition of methyl groups so that DNA is more tightly packed around the histones and can't be transcribed
93
What is acetylation? (Unit 6)
The addition of acetyl groups to open up the chromatin structure, promoting the initiation of transcription
94
How is gene expression regulation different in prokaryotes and eukaryotes (Unit 6)
Prokaryotes --> operons
Eukaryotes --> transcription factors, activators, enhancers, mediator proteins
95
How are genes regulated in prokaryotes? (Unit 6)
The operon can be switched on or off by a repressor
A corepressor binds to the repressor to switch off an operon
An inducer binds to the repressor to switch on an operon
96
How does genetic drift affect a population's genetics over time? (Bottlenecks and founder effect) (Unit 7)
Genetic drift is the random change in the frequency of an allele
Bottleneck → a bottleneck event causes a large/diverse population to be suddenly reduced to a small population
Founder Effect → Reduces genetic variation due to separation from a larger population
97
How does gene flow affect a population's genetics over time? (Unit 7)
Gene flow introduces new genes into a population, can either reduce or increase genetic diversity
98
Sympatric vs allopatric speciation (Unit 7)
Allopatric → evolution of a new species due to geographic isolation
Sympatric → evolution of a new species due to reproductive isolation
99
What are K-selected organisms? (Unit 8)
Produce few offspring in areas of high population density
100
What are r-selected organisms? (Unit 8)
Produce many offspring in areas of low population density
101
What is the importance of the active site in an enzyme? (Unit 3)
Enzymes catalyze a specific reaction with a specific substrate which fits perfectly into the active site
102
What would happen if the enzyme's active site changed? (Unit 3)
The substrate would no longer fit in the active site, wouldn't be able to catalyze the reaction
103
What does an enzyme do to catalyze a reaction? (what changes, what stays the same) (Unit 3)
Changes:
- lower energy barrier (takes less energy for the reaction to occur)
Doesn't change:
- reactants or products
- free energy
- whether the reaction releases or absorbs energy
104
What things can impact enzyme activity? (Unit 3)
- enzyme concentration
- substrate concentration
- temperature
- pH
- enzyme inhibitors
105
How does enzyme concentration impact enzyme activity? (Unit 3)
more enzymes = increase in enzyme reaction rate, substrates interact/collide with enzymes more often
106
How does substrate concentration impact enzyme activity? (Unit 3)
more substrates = increase in reaction rate, enzymes and substrates interact/collide more often
107
How does temperature impact enzyme activity? (Unit 3)
- enzymes have an optimal temp for maximum reaction rate
- low temps = slower rate
- high temps = denaturation if too high
108
How does pH impact enzyme activity? (Unit 3)
- enzymes have an optimal pH for maximum reaction rate
- high pH = decreased enzyme activity
- low pH levels can cause denaturation of the enzyme
109
How do inhibitors impact enzyme activity? (Unit 3)
General
- certain chemicals inhibit enzyme function
- covalent bonds = irreversible inhibition
- weak interactions = reversible
Competitive
- looks like substrate and binds to the active site, stops the real substrate
- increasing substrate concentrations can overcome bonds
Noncompetitive
- not bound to the active site
- change the shape of the enzyme making it less effective
110
What are the inputs and outputs of a light dependent (Unit 3)reaction?
Inputs:
Water (H2O), light energy, NADP+, ADP + phosphate ion
Outputs:
NADPH, ATP, oxygen
111
What are the inputs and outputs of a light independent reaction? (Calvin Cycle) (Unit 3)
Inputs:
CO2, ATP, NADPH
Outputs:
G3P (a 3 carbon sugar) which will later be glucose, ADP + phosphate ion, NADP+
112
Where does the light dependent reaction take place? (Unit 3)
Thylakoids of chloroplasts
113
Where does the light independent reaction take place? (Calvin Cycle) (Unit 3)
Stroma of chloroplasts
114
What is the main purpose of the light dependent reaction? (Unit 3)
Captures energy from the sun to create ATP and NADPH for use in the light independent reaction
115
What is the main purpose of the light independent reaction? (Calvin Cycle) (Unit 3)
Uses ATP and NADPH to produce carbs/sugars from CO2 taken in
116
What are the photosystems and why are they important? (Unit 3)
- they are proteins embedded in the thylakoid membranes
- chloropyll pigments absorb light to excite electrons
117
What would happen if the proton gradient in photosynthesis was not working? (Unit 3)
If the proton gradient stops working then ATP will not longer be produced for the light independent reaction to occur
118
What is the importance of the proton gradient in photosynthesis and how is it created? (Unit 3)
- As electrons are transferred down the ETC H+ ions are moved into the thylakoid
- the H+ ions then leave the thylakoid through ATP synthase from high to low concentration to create ATP
119
What is the origin of photosynthesis? (Unit 3)
- First evolved in prokaryotic cells
- moved to eukaryotic cells due to endosymbiosis
120
What are the inputs and outputs of glycolysis? (Unit 3)
Inputs:
Glucose
Outputs:
2 pyruvate, 2 ATP, 2 NADH
121
Where does glycolysis take place? (Unit 3)
In the cytosol
122
What is the main purpose of glycolysis? (Unit 3)
The first step for both cellular respiration and fermentation, extract electrons and move them to NADH And FADH2 which is used in the ETC
123
What are the inputs and outputs of the citric acid/krebs cycle? (Unit 3)
Inputs:
Acetyl CoA
Outputs:
NADH, FADH2 and ATP, CO2
124
Where does the citric acid/krebs cycle take place? (Unit 3)
The mitochondrial matrix
125
What is the main purpose of the citric acid/krebs cycle? (Unit 3)
Extract electrons and move them to NADH and FADH2 which is used in the ETC
126
Where is the electron transport chain? (Unit 3)
The inner membrane of the mitochondria
127
What is the main purpose of the electron transport chain? (Unit 3)
- series of small reactions that release small amounts of energy to bring in H+ ions
- Oxygen accepts the electron at the end and forms water
128
What is oxidative phosporylation and what is it's main purpose? (Unit 3)
- As the electron goes down the ETC H+/protons pass across the membrane to reach equilibrium
- ATP synthase forms ATP from ADP + P
- Oxidation = NADH/FADH2 lose electrons
- Phosphorylation = ADP + P --> ATP
129
What are the inputs and outputs of fermentation? (Unit 3)
Inputs:
glucose, 2 ATP
Outputs:
Lactic acid or alcohol and CO2
130
Aerobic vs anaerobic respiration (Unit 3)
Anaerobic = needs oxygen (most of cellular respiration)
Aerobic = doesn't need oxygen (fermentation)
131
What is the importance of the proton gradient and how is it created? (cellular respiration) (Unit 3)
protons are pumped across the inner mitochondrial membrane, it is pumped back out through ATP synthase to make ATP
132
What can the proton gradient be used for other than the production of ATP? (Unit 3)
Energy from the proton gradient can be used to generate heat/regulate body temp instead of going through ATP Synthase
133
What is unique about fermentation? Why is that important? (Unit 3)
Doesn't require oxygen, starts with glycolysis but doesn't go through the Krebs cycle or the ETC
134
What is the main goal of cellular respiration and fermentation? (Unit 3)
To make ATP for use in the cell from stored sugars and carbs
135
What is the main goal of photosynthesis? (Unit 3)
Allows plants to make food using light energy which is converted into chemical energy
136
Why is ATP important? (Unit 3)
When it is converted into ADP it releases energy for use within the cell
137
Endergonic vs exergonic (Unit 3)
Endergonic
- releases energy (still requires a little energy input for the reaction to occur)
- spontaneous
- products have LESS free energy than reactants
Exergonic
- absorbs energy
- non-spontaneous
- products have MORE free energy than reactants
138
Oxidation vs reduction (Unit 3)
Oxidation = losing electrons
reduction = gaining electrons
