Biology Flashcards
(205 cards)
1
Q
True or false: mitochondrial DNA is double stranded
A
TRUE: mitochondrial DNA are double stranded
2
Q
Which of the following organelles is membrane bound, lysosomes or ribosomes?
A
Lysosomes are membrane bound
Ribosomes do not have membranes- they are found in prokaryotes which lack membrane bound organelles
3
Q
What is a mature sperm cell called?
A
Spermatozoan
4
Q
What is the product of the first meiotic division?
A
Meiosis I, or reductional division, results in 2 haploid (n) daughter cells
5
Q
When in meiosis do the dividing cells become haploid?
A
Telophase I is the last time when cells are diploid- first meiotic (reductional) division results in 2 haploid daughter cells
6
Q
What happens to GnRH levels during pregnancy?
A
GnRH induces FSH/LH secretion from anterior pituitary- high estrogen and progesterone inhibit GnRH to prevent onset of new menstrual cycle
7
Q
Which of the following developmental stages has the greatest nuclear to cytoplasmic ratio?
Eight-cell embryo, morula, blastula, zygote
A
Blastula- embryo volume does not increase significantly until after implantation (implanted cell is zygote)
8
Q
Why would feral hemoglobin not be found in a maternal blood test?
A
Hemoglobin is a large protein that cannot pass through placenta
9
Q
A patient presents with hyponatremia and ambiguous genitalia. Which endocrine organ is most likely affected?
A
Adrenal cortex (sugar, salt, sex)
10
Q
Patients with emphysema have difficulty exhaling completely. Why is this?
A
Emphysema causes destruction of alveolar walls, which decreases recoil of lung tissue
11
Q
Which of the following is a brush border enzyme:
Carboxypeptidase, trypsin, chymotrypsin, aminopeptidase
A
Aminopeptidase is a brush border enzyme
12
Q
What is the purpose of creating urine that is hypertonic to the blood?
A
Helps retain water
13
Q
Describe how to find the frequency of a dominant or recessive allele given the percent of the population that is homozygous dominant/ recessive
A
Take the square root of the frequency
If 9% of population is homozygous dominant, the dominant allele has a frequency of 30%
p2 + 2pq + q2 = 1
14
Q
If 9% of the population is homozygous dominant, what is the frequency of the recessive allele, the portion of the population that is heterozygous, and the proportion of the population with a dominant phenotype?
A
Frequency of dominant allele is square root of 0.09, so 0.3/30%
So the frequency of the recessive allele is
.3 + x = 1 so 0.7
2pq = heterozygous population, so 2x0.3x0.7 = 0.42
p2 + 2pq is population with dominant phenotype, so 0.09+0.42 = 0.51
15
Q
A male with hemophilia (XhY) is crossed with female carrier of both color blindness and hemophilia (XcXh)- what is the probability that a female child will be phenotypically normal?
A
50%- two daughters of 4 offspring, 1 will be a carrier of both (XcXh)
16
Q
What is the minimum inhibitory concentration?
A
MIC is least amount of drug/inhibitor needed to be effective
17
Q
Why do virions carry RNA polymerase?
A
Eukaryotic host cells cannot synthesize RNA from RNA
18
Q
Anti-sense mRNA is identical to what
A
Anti-sense mRNA is same as template strand
Both are complements to mRNA transcript
19
Q
Where are the replicated chromosomes in meiosis I, and how many are there?
A
Meiosis I begins with 4 replicated chromosomes/ 2 pairs of homologues (tetrads) aligned in homologous pairs across from each other at the equatorial plate
20
Q
A normal mother is crossed with a X-linked dominant affected father. How many sons and daughters will be affected, respectively?
A
All unaffected sons (will receive normal X from mother) and all affected daughters (X dominant)
21
Q
If a primer sequence is ATG GCC TCT, what is the complementary sequence? What is the mRNA sequence?
A
Primer —> complementary sequence in same direction with complementary nucleic acids:
TAC CGG AGA
Complementary sequence is transcribed to mRNA with original nucleic acids except U instead of T:
AUG GCC UCU
22
Q
What type of accommodation do the eye lens provide?
A
Ciliary muscles control lens curvature to accommodate focal point
Lens accommodation is for distance only
23
Q
How do the pH values of the matrix and intermembrane space compare?
A
Intermembrane space is more acidic due to proton pumping
24
Q
What is the result of mitochondrial uncouplers?
A
Decreased ATP production
25
True or false: mitochondria are the only organelles involved with lipid metabolism
FALSE: peroxisomes contribute to lipid metabolism
26
Where are desmosomes likely to be found (characteristically, regarding their function)?
Desmosomes: weld cells together, found in stratified epithelium in tissues subject to stress
27
What are chromatin made of?
DNA + proteins
28
What does meiosis yield?
4 genetically distinct, haploid daughter cells
29
Which one is correct?:
AT- 3 H bonds
GC- 2 H bonds
GC- 3 H bonds
GC- 3 H bonds, why it’s so strong
AT- 2 H bonds
30
What are the pyrimidines, and what is their defining feature?
Pyrimidines- thymine, uracil, cytosine
1 ring (purines have 2 rings)
*pies have 1 ring of crust
31
What piece of information must be known to perform PCR?
Target DNA sequence
32
Describe the effect/ reason for genetic imprinting?
Gene expression different depending on which parent the gene came from
33
What would be the effect of a pleiotropy gene?
Single gene contributes to multiple phenotypic traits
34
What phenotypic ratios should you get for a dihybrid cross? For a monohybrid cross?
Dihybrid cross-> 9:3:3:1
| Monohybrid cross-> 3:1
35
Which of the following would not be found in higher concentrations in cancer cells?
Mitochondria
Chromosomes
Lysosomes
Chromosomes- chromosomes are replicated during cell division but number of chromosomes is the same (concentration is the same)
36
What is a nucleosome?
4 histone proteins wound together
37
What is the number of chromosomes per human cell at the end of meiosis I, mitosis, and meiosis II?
23, 46, 23
Sister chromatids are not counted as separate chromosomes (dyad = 1 chromosome)
38
```
Which of the following is not a component of DNA strand?
Nitrogenous base
Phosphodiester linkage
Amines
Disulfide bonds
Hydrogen bonds
```
Disulfide bonds- folded proteins, not DNA strand
39
Patient with HSV presents with no symptoms. What cycle is the virus in?
Lysogenic cycle = dormant
40
Viruses evolve faster than all other systems. Why?
Viruses lack proof reading- highest mutation rate
41
```
Which of the following are true of most fungi?
Cell walls with chitin
Haploid during large portion of life
Digest food before absorbing it
Sexual and asexual reproduction
```
All true!
42
If the coding strand is
5’ATTCG3’
What is the Pre-mRNA?
3’GCUUA5’
43
Which is not true of bacteria?
Gram + have 2 cell membranes
Gram - stain pink and have thinner cell walls
Gram + stain purple and have peptidoglycan cell walls
All bacteria contain organelles
All are true (nucleus and ribosomes are organelles!) except first
Gram + have 1 cell membrane, gram - have 2
44
Where are the cones located in the eye?
Fovea
45
What are the respective sizes of eukaryote and prokaryote ribosomes?
Human- 60S and 40S, 80S total
Prokaryote- 50S and 30S, 70S total
(Just remember to add/subtract 10)
46
What’s left in your lungs after forced exhalation?
Residual volume
47
In what vasculature is velocity the slowest?
Capillaries- greatest total cross section. Allows time for nutrient exchange
48
Name the granulocytes
Neutrophils, eosinophils, basophils
49
Describe the metabolism of neurons (where do they get their energy)
Depend entirely on glucose, insulin independent
Very low glycogen and oxygen storage capability- require high perfusion (rate of blood flow)
50
Just before max depolarization is reached, what ion channel begins to close, which begins to open?
Right before max depolarization- Na+ channels close, K+ channels open
51
What are the neurotransmitters of the sympathetic and parasympathetic nervous division?
Sympathetic: acetylcholine at ganglia (far from effectors), norepinephrine at effector
Parasympathetic: acetylcholine
52
Are norepinephrine and epinephrine water or lipid soluble?
Water soluble
Tyrosine derivative, from adrenal medulla
53
Name the lipid soluble hormones (hint- 5 total, from 2 organs)
Aldosterone (adrenal cortex)
Cortisol (adrenal cortex)
Testosterone (testes)
Estrogen (ovaries)
Progesterone (ovaries)
54
Which hormone causes sodium reabsorption at the distal convoluted tubule and collecting duct?
Where is the hormone from?
What type of hormone is it?
What’s it’s solubility?
Aldosterone
Adrenal cortex
Steroid hormone
Lipid soluble
55
True or false: the peptide hormones are all water soluble
True
56
Which hormone causes a surge in LH during menstruation?
What kind of hormone is it, what’s it’s solubility?
Estrogen
Steroid, lipid soluble
57
Which hormone causes production of sperm?
What organ is it from, what kind of hormone is it, what’s it solubility?
FSH
anterior pituitary (FLAT PEG)
Peptide/ water soluble
58
Which is the correct path of an action potential in the PNS?
- dendrite, cell body, axon hillock, axon, Schwann cell, node of Ranvier, terminal bouton, synaptic gap
- dendrite, cell body, axon hillock, axon, terminal bouton, synaptic gap
- dendrite, cell body, axon hillock, axon, oligodendrocyte, terminal bouton, synaptic gap
dendrite, cell body, axon hillock, axon, Schwann cell, node of Ranvier, terminal bouton, synaptic gap
(Oligodendrocytes are CNS, also need to include Nodes of Ranvier)
59
You carb up for hibernation! Which hormones will be in high concentrations during fall and winter, respectively?
- insulin, then glucagon
- glucagon, then insulin and cortisol
- insulin, then glucagon and cortisol
-insulin, then glucagon and cortisol
Cortisol promotes gluconeogenesis and fat metabolism
60
In which PNS division, sympathetic or parasympathetic, has cell bodies located far from the effector?
Sympathetic neuron cell bodies are far from the effector
Parasympathetic cell bodies are close to effector
61
True or false: flow rate is at maximum in the aorta
FALSE: according to Q=AV, flow rate is constant in a closed system
62
```
Patient develops a disease caused by hypoactivity of anterior pituitary. Which hormone won’t necessarily be in low concentrations?
ACTH
TSH
Prolactin
Oxytocin
```
FLAT PEG
oxytocin is not anterior pituitary (it’s from posterior pituitary)
63
```
Which is NOT an effect of increased ACTH?
Decreased glycolysis
Increased cortisol
Increased blood glucose
Decreased insulin
```
Decreased insulin is not likely
ACTH stimulates glucocorticoid secretion from adrenal cortex (stress hormones)—> increased gluconeogenesis and fat metabolism. More blood glucose would cause increased insulin
64
Will TSH dissolve through the nuclear membrane or bind to membrane receptor?
TSH is peptide hormone/ water soluble
Will bind to membrane receptor (polar), initiate GPCR cascade
65
What does breathing into a paper bag do?
Increase blood CO2, Decrease blood pH
CO2 + H2O <> HCO3- + H+
66
How does rapid breathing after exercise affect blood chemistry?
Increased blood pH because loss of CO2 from the blood
67
Which describes starling forces of arteriolar and venous sides of capillary, respectively?
- high hydrostatic/low osmotic, low hydrostatic/low osmotic
- low hydrostatic/low osmotic, high hydrostatic/high osmotic
- high hydrostatic/low osmotic, low hydrostatic/high osmotic
Arteriolar: high hydrostatic/low osmotic
Venous: low hydrostatic/high osmotic
Osmotic pressure increases so at venous end there is net flow into capillary (already dropped off the nutrients on arteriolar side)
68
Does aldosterone affect sodium réabsorptions at the distal convoluted tubule, or water permeability at the collecting duct?
Aldosterone—> sodium réabsorptions
| ADH- water permeability
69
Oxidative phosphorylation vs substrate level phosphorylation- what’s different?
Oxidative phosphorylation has to do with sharing electrons with oxygen, pretty much exclusive to ETC and ATP synthase
Substrate level phosphorylation- any other phosphorylation event, glycolysis and TCA good examples
70
How many electrons does cytochrome c transport in oxidative phosphorylation?
1
Fe2+ —> Fe3+
71
What type of primer is good for PCR?
Lots of GC content on ends- more stable with 3 H bonds
72
When does nondisjunction occur in meiosis?
Anaphase I
73
How does increasing the concentration of a transporter change its affinity for its substrate?
It doesn’t! Affinity stays the same
74
What secretes epinephrine and norepinephrine? What types of hormones are these?
Adrenal medulla
Tyrosine derivative
Water soluble
75
What is a reasonable result of transfection with a retroviral expression vector?
Enhanced transcription
Enhanced translation
Enhanced transcription and possible enhanced translation
Enhanced transcription and possible enhanced translation
Adding in a viral vector, so transcription will happen, but can’t assume translation (other things could occur after transfection)
76
If there are x number of H2B histone proteins in a cell, hoe many H1 proteins are expected?
0.5x
2 of each core histone, only 1 linker (H1) protein
77
```
Which of these (one or multiple) would be found at the site of infection 15 hours post-infection?
DC
macrophages
Neutrophils
T cells
B cells
```
DC
neutrophils
Macrophages
78
```
If HLA II is absent from a patients cells, which of these cannot be performed?
Phagocytosis
Antigen presentation to T cells
Antigen presentation to B cells
Inflammation
```
Antigen presentation to T cells
79
Which are both in prokaryotes and eukaryotes? (One or multiple)
Cell walls
Ribosomes
DNA
All
Plants and fungi are eukaryotes- have cell walls
80
Which can cause depolarization of postsynaptic neuronal membranes?
Acetylcholine
Glutamate
Both (both excitatory)
Glutamate just does depolarization, ACh can do re/depolarization depending on where it is in the body
81
Which effects speed of action potential?
Axon diameter
Axon length
Axon diameter only
82
True or false: both introns and exons are included in primary mRNA transcript
True. Introns are removed during post-transcriptional processing.
Primary mRNA transcripts are shorter than genes because regulatory sequences are not transcribed
83
Which is higher in the resting cell, sodium or potassium?
Potassium, sodium is much higher outside of the cell
Sodium potassium pump moves sodium out, potassium in (against concentration gradient)
84
You see a patient with nerve injury. The injured nerve has its cell body near its effectors. What kind of nerve is it?
Parasympathetic nervous system
Sympathetic neurons have cell bodies far from effector
85
```
Which of these hormones is not likely to diffuse through the cell membrane and enter the nucleus?
Aldosterone
Triiodothyronine
Cortisol
Epinephrine
```
Epinephrine and norepinephrine are secreted from adrenal medulla, water soluble tyrosine derivatives
The rest are lipid soluble
86
What’s most likely different about homologous genes between humans and bacteria?
Have almost identical DNA sequences
But respective binding interactions between other proteins cannot be inferred
87
Under anaerobic conditions, pyruvate is converted to lactate why?
To regenerate NAD+ so glycolysis can continue
88
What happens to water if you increase the Kw?
Kw = [H+][OH-] = 1x10^-14
If Kw is increased than pH would decrease because there would be a higher concentration of hydrogen
89
Give an example of a DNA palindrome
DNA palindromes read same from 5’-3’ on one strand as they do 5’-3’ on complementary strand
Example:
5’-GAATTC-3’ and complement strand of
5’-CTTAAG-3’
90
What would oligomycin do to oxygen consumption?
ATP synthase inhibitor- decreased oxygen consumption
Uncoupler would increase oxygen consumption
91
Biologists label sulfur and introduce it into bacteriophage proteins, then inoculate cultured bacteria with labeled phases. Will radiolabeled sulfur be detected in bacterial proteins from cytosol fraction or viral coat proteins from extra cellular fraction?
Viral coat proteins
Sulfur is not found in nucleic acid so won’t be injected into bacteria (only inject genetic material)
92
Describe the cori cycle
Glucose is transported from liver to muscle. NAD+ is reduced to NADH while glucose becomes pyruvate and ATP is released (glycolysis)
In liver NAD+ can be reduced to convert lactate to pyruvate. Pyruvate can be converted to glucose in liver using ATP (gluconeogenesis)
93
Dp equilibrium constants for reactions include solids in the expression
No
Solids are In a different phase
94
Single somatic motor neuron innervates single/group of muscle fiber? What would a group of muscle fibers be called? What are fascicles?
Single somatic motor neuron innervates group of muscle fibers, called motor unit
All receive same frequency as action potential
Fascicle- large group of bundled muscle fibers
95
Can H-H hydrogen bond
No, no dipole moment
| H must be bonded to F, O, or N
96
How many daughter cells will be normal if nondisjunction occurs in anaphase I? What about anaphase II?
Anaphase I- none of 4 daughter cells will be normal. Duplicated copies of both homologues in one cell (homologous pairs supposed to separate here)
Anaphase II- 2 normal cells. 1 of daughter cells will have 2 copies of chromosomes, 1 will have neither copy
97
What reaction breaks down macromolecules in digestion?
Hydrolysis
98
Which cells in the intestines and respiratory tract secrete mucus?
Goblet cells
Mucus cells secrete mucus in stomach
99
What do chief cells secrete?
Zymogen pepsinogen- low pH of stomach cleaves to pepsin
100
What do parietal and g cells secrete, respectively?
Parietal- HCl
G cells- gastrin. Released into BLOOD and circulates back to parietal and chief cells (pepsinogen) to stimulate them
101
What type of hormone is gastrin, and will it bind a membrane receptor?
Peptide- yes binds receptor on membrane
102
Glucagon stimulates ___, insulin stimulates ___ (both in liver)
Glucagon- glycogenolysis
Insulin- glycogenesis
103
```
What are the 6 pancreatic digestive enzymes?
2 for protein
1 for carbs
1 for fat
2 for nucleic acids
```
Trypsin
Chymotrypsin
Pancreatic amylase
Lipase
Ribonuclease, deoxyribonuclease
104
Where do pancreatic enzymes empty into?
Duodenum- most of digestion occurs here
105
What is mutualism? Give an example from the body
Symbiosis where both parties benefit
Ex- commensal bacteria in GI
106
Where does carb digestion begin? Proteins? Lipids? By what enzymes?
Carbs- mouth, salivary amylase
Proteins- stomach, pepsin and HCl
Lipids- duodenum, pancreatic lipase
107
What are the 2 ways lipids are transported in blood or lymph?
Bound to carrier protein (albumin)
Formed into chylomicron or micelle
108
What are the granulocytes?
Never Eat Bananas
Neutrophils (phagocytic)
Eosinophils (parasitic infections)
Basophils (rare, allergy)
109
What 2 cells are involved in allergy response and how do they differ?
Basophils- recruited (granulocytes are recruited)
Mast cells- resident of tissues
110
What are the APC?
Macrophages
DC
B cells
111
B cells become what after activation/ replication?
Plasma cells (clones)
Secrete antibodies
112
What do helper T cells do?
Stimulate original B cells to divide into a plasma cell and a memory B cell
113
A muscle group is a bundle of many ___
Repeating units of actin and myosin fibers are ___
Fasciculi
Sarcomeres
114
Myosin binds actin except when blocked by ___
Tropomyosin
115
What is the only neurotransmitter used at the neuromuscular junction?
ACh
116
When calcium is released from the SR, it binds ___, freeing the binding site from ___ which allows ___ to bind ____
When calcium is released from the SR, it binds troponin, freeing the binding site from tropomyosin which allows myosin to bind actin
117
What does ATP binding allow to happen in muscular contraction?
ATP binds to myosin head, facilitating its release from actin filament
ATP hydrolysis gives energy to cock myosin head
118
In muscular contraction, what happens if no ATP is present? What happens if no calcium is present?
No ATP- rigor mortis- myosin heads cannot detach from actin, stuck in contracted position (straight)
No calcium- flaccidity- inability to contract
119
What does the acrosome do in sperm?
Contains hydrolytic enzymes to penetrate ovum
120
What is an example of positive feedback in the menstrual cycle?
LH stimulates estrogen (estradiol) secretion
Normally estrogen inhibits LH
but day 14, estrogen induced LH surge (luteal surge)
121
How do menstruation and ovulation differ in hormone levels?
Menstruation caused by drop in hormone levels
Ovulation caused by surge in hormone levels
122
How many cells are in morula?
8 celled zygote
123
do peripheral and autonomic nervous systems develop from ectoderm, mesoderm, or endoderm?
Ectoderm
124
Most internal organs develop from:
Ectoderm
Mesoderm
Endoderm
Mesoderm
125
What regulates pepsin secretion
Gastrin (endocrine hormone) secreted by g cells
126
Inability to polymerize tubulin most directly affects:
Cilia in microvilli of small intestine
Ependymal cells in cerebrospinal fluid
Cell division in myocytes
Ependymal cells in cerebrospinal fluid
| Microvilli not made of cilia, mature myocytes don’t divide
127
Where does bicarbonate secretion occur:
Mouth
Duodenum
Both
Duodenum
pH of mouth maintained by buffer
128
Where does primary absorption of water and vitamins occur
Large intestine
129
___ produces bile
| ___ stores bike
Liver produces
| Gallbladder stores
130
How does decreased FSH affect GnRH
Decreased FSH increases GnRH due to loss of negative feedback
131
___ is bound to actin until calcium replaces it
Tropomyosin
132
Liver, pancreas, and gallbladder are part of what germ cell layer
Endoderm
133
Fasciculi are bundles of ___
T tubules are invaginations in ___
Fasciculi- muscle fiber bundles
T tubules- invaginations in sarcolemma (NOT SER)
134
Sperm production occurs where
Seminiferous tubules
Nurtured/ stored in epididymis
135
Hematopoeisis occurs in spongy or compact bone?
Spongy
136
ATP hydrolysis used to muscle contraction why
To transition myosin head from bent to straight (low to high energy position)
137
Where is myosin head before calcium enters Sarcomere
Cocked, not attached to actin
Calcium displaces tropomyosin, myosin grabs actin and relaxes to bent position, drags actin with it
138
Which of these will occur with starvation?
Elevated cortisol
Insulin resistance
Both
Insulin resistance to save glucose for essential organs (brain)
139
What are the 3 fates of water-insoluble waste products?
Stored
Converted to water soluble
Eliminated in feces
140
How does acidemia affect hemoglobin’s affinity for oxygen?
Left or right shift on curve?
Acidemia = DECREASED oxygen affinity in order to allow it to be given up more freely in tissues (because blood CO2 is too high)
Binding of H+ to oxyhemoglobin enhances oxygen release
RIGHT shift
141
How much ATP does fermentation produce?
2 ATP, both from glycolysis
142
Man with AB blood has child with women of type O. What blood types can the children have?
A or B
Child will inherit either AO or BO
143
Neural crest is derived from
Ectoderm
144
In lac operon, repressor binds __
Repressor binds operator
| Not promoter gene- site of binding for RNA Pol
145
Following action potential, calcium binds ___
Calcium binds TROPONIN complex
This allows tropomyosin to expose myosin binding sites on actin
146
What part of nephron is glucose reabsorbed?
Proximal convoluted tubule
147
Cofactor
Molecule NECESSARY for enzyme activity that isn’t an enzyme itself
148
What kind of bond does UDP-glucose form
UDP-glucose reacts with non reducing end of lengthening glycogen polymer
Forms alpha-1,4-glycosidic bond
149
how does axon hillock respond to simultaneous excitatory and inhibitory signals
sums them
| depolarization occurs if signal is sufficient to exceed threshold potential
150
when ADH acts on collecting ducts in response to dehydration, osmolarity of ascending limb of Loop of Henle will:
increase
decrease
remain the same
decrease
ADH increases water reabsorption, so more water is in medulla
more dilute medulla shifts equilibrium between filtrate in ascending limb and medulla, driving ions out of ascending limb (decreasing osmolarity)
151
ascending limb is permeable to ___, impermeable to ___
ascending limb- permeable to water, impermeable to ions
152
compare gram negative and gram positive by 3 features
GRAM NEGATIVE- peptidoglycan, 2 membranes, LPS
gram positive- thick peptidoglycan, 1 membrane, no LPS
153
ribosomes bound to RER make ___
| free floating ribosomes make ___
RER ribosomes- hydrolytic enzymes for lysosomes and proteins to be secreted
free floating- all other proteins to be used inside cell
154
small intestine parts in order
duodenum -> jejunum -> ilium
| Does Jumping Increase [digestion]?
155
which enzyme removes RNA nucleotides from primer and adds DNA nucleotides to 3' end of Okazaki fragments?
DNA pol
| ligase just seals afterwards
156
where are action potentials generated in muscles
sarcolemma- contains voltage-gated channels
157
where does ribosome synthesis and assembly occur
nucleolus
158
what do you need to know to design PCR
length of gene and nucleotide sequence
159
What’s another name for actin
Microfilament !!!
160
tubulin
globular protein assembled from microtubules
161
a bacterium consumes lactose, resulting in activation of lac operon, which results in:
- dissociation of lac repressor from operon
- association of lac regulatory protein with operon promoter
- degradation of lac repressor
association of lac regulatory protein with operon promoter- when lactose is present, it binds lac repressor, causing repressor to dissociate from the lac operon, allowing transcription to occur
lac regulatory protein is a REPRESSOR- must be removed
162
orientation of mRNA codon to tRNA anticodon is
antiparallel
163
gastrin (G) cells are:
endocrine
neurosecretory
endothelium
endocrine
| neurosecretory can only be neurons
164
decrease in FSH would decrease all but:
estrogen
sperm production
GnRH
GnRH- would cause increase because of lack of negative feedback
(FSH stimulates follicle to release estrogen)
165
```
which is not derived from mesoderm?
heart
lungs
liver
peritoneum
```
liver
(liver and pancreas are from endoderm)
(mesoderm is mostly organs and their linings, except for these)
166
fasciculi
bundles of muscle fibers
167
complete lack of ATP and complete lack of calcium have what effect on skeletal muscle, respectively?
lack of ATP = rigor (myosin head cannot separate from actin after power stroke)
lack of Ca2+ = flaccid paralysis (tropomyosin cannot be displaced from actin)
168
effect of point mutation to terminal guanine on 5' exon?
intron will not be spliced. first step of intron splicing is nucleophilic attack of 2'hydroxyl at phosphate of guanine at end of 5' exon (to form lariat)
169
growth factors regulate what cell cycle checkpoint
G1- controls transition to S phase
170
where does translation occur in prokaryotes
cytoplasm- they have no nuclear membrane. ribosomes are involved but they are not a cellular compartment
171
what is different about anaphase of mitosis and meiosis?
anaphase of mitosis- sister chromatids pulled apart at centromeres
anaphase I of meiosis- homologous pairs are separated but remains two sister chromatids joined at centromere (centromeres don't split until anaphase II)
172
which 3 sources of hormonal secretion are important for the menstrual cycle?
```
hypothalamus (GnRH)
anterior pituitary (FSH and LH)
ovary (estrogen, progesterone)
```
173
what hormone triggers ovulation
LH surge
174
how are estrogen and progesterone secretion related to LH
estrogen- triggers LH surge (which triggers ovulation)
| progesterone- secreted in response to LH
175
histone acetylation
neutralizes positive charges on histones by acetylating lysine residues, disrupting their ability to bind negative DNA
176
how does amount of genetic material compare for somatic and germ cells
somatic- diploid, germ- haploid
| germ have half genetic material of somatic
177
degraded viral peptides transported to ER via TAP protein and presented as antigens by MHC I on cell surface. MHC protein complex made in free floating ribosome or RER?
RER used for excreted proteins/ cell surface proteins
178
where are lymphocytes and all blood cells made
red bone marrow (yellow bone marrow is adipose!)
179
cell undergoing mitosis has 32 chromatids visible at end of prophase. what is its diploid number?
16. at this point DNA has been duplicated
180
which will not be found in prokaryotic membrane?
| proteins, glycolipids, sterols, phospholipids
glycolipids and sterols
181
where does proteasomal degradation occur
cytoplasm !!!
182
water acts as a ___ in hydrolysis reactions
nucleophile
183
palindrome
same nucleic acid sequence on both sides of double stranded DNA going in opposite directions
184
transcription factors bind at ____ which is always upstream of ____
transcription factors bind promoter, always upstream of coding sequence
185
what migrates on the gel after RT-PCR
RT-PCR uses RNA template to produce cDNA, further amplification results in double-stranded DNA which is what migrates on gel
186
compare the transport mechanisms of aldosterone and ADH
aldosterone- active transport. can increase salt reabsorption no matter blood solute concentration
ADH- alters passive water uptake via aquaporins in collecting duct
187
explain why prokaryotes can't do mRNA splicing
transcription is in cytoplasm and ribosomes bind and begin translation before transcription is even complete
188
how many electrons does cytochrome c carry
1 at a time!
189
what are the 3 amino acids that carry 2 N atoms, yet are neutral at neutral pH
asparagine, glutamine, tryptophan
190
what are the 2 parts of a fatty acid (head and tail portions)
long hydrocarbon tail + carboxylic acid head
191
which is mediated by ligand-gated ion channel?
- release of Ca2+ from sarcoplasmic reticulum
- influx of Na+ across motor end plate
- re-entry of Ca2+ into sarcoplasmic reticulum
influx of Na+ across motor end plate occurs when Na+ ion channels bind ligand Ach
192
how does Southern blot detect mutant vs WT?
Southern blot uses restriction digest
restriction sites are palindromes (symmetrical), so Southern blot will detect a mutation in a palindrome
(HindIII recognizes AAGCTT)
193
a mutation is present only in cancerous tissue of a patient. what does this say about mutation?
somatic mutation, not germline
194
nicotinamide nucleotide
NADH
195
free energy is ____ property, activity is ____ property
free energy = thermodynamic
| activity = kinetic
196
what is role of Na+K+ ATPase in action potentials
restores resting membrane potential
| 3 Na+ out, 2 K+ in with each ATP hydrolyzed (against concentration gradient)
197
transcription factors bind ___, recruit ___
bind DNA, recruit RNA pol
198
what kinds of molecules freely diffuse through cell membrane
nonpolar (LIPID bilayer)
199
initial filtration in glomerulus occurs by
passive flow due to pressure difference- blood pressure forces fluid from glomerulus into lumen of Bowman's capsule
200
name 3 ways enzymes work
co-localize substrates
alter local pH
alter substrate shape
201
main input of Kreb's cycle
acetyl coenzyme A (acetyl CoA)
202
do prokaryotes have telomeres
no, they have circular DNA
203
how do glucocorticoids affect muscles
cause breakdown of muscle proteins
204
when is gluconeogenesis primarily used
when blood carb is low, because it makes glucose out of other molecules
205
transduction vs transformation vs conjugation (bacteria)
transduction- genetic info via virus vector
transformation- genetic info via picking it up in the environment
conjugation- sex pillus (F+ --> F-)
