Bio + Biochem Flashcards
1
Q
How is PFK 1 inhibited by ATP?
A
ATP downregulates through feedback inhibition the activity of phosphofructokinase-1 by binding to a regulatory site other than the active site of the enzyme
2
Q
Facilitated Diffusion also called
A
passive transport
3
Q
Where are secretory proteins synthesized?
A
in the rough endoplasmic reticulum
4
Q
Where are transcription factors found?
A
The nucleus
5
Q
What does ubiquitination do?
A
targets a protein for degradation by a proteasome.
6
Q
GAPDH catalyzes which reaction?
A
a glycolytic enzyme that catalyzes the reversible conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate.
7
Q
What experimental method would you use to determine difference after protein modification?
A
Western blot
8
Q
Antioxidant Enzymes
A
Fight against reactive oxygen species
9
Q
vasopressin
A
regulates the fusion of aquaporins with the apical membranes of the collecting duct epithelial cells
10
Q
blood from the small intestine is transported first to the…
A
first to the liver, which regulates nutrient distribution and removes toxins from the blood
11
Q
Endosomes
A
mediate internalization of viral particles through endocytosis
12
Q
What is the purpose of the sodium potassium pump?
A
To maintain membrane potential
13
Q
How many molecules of ATP are produced in glycolysis?
A
2 ATP (and 2 NADH)
14
Q
What happens during inflammation?
A
white blood cells (leukocytes) will fight infection or debris
15
Q
What happens when a person has high blood glucose?
A
Insulin stimulates glycogen synthase to form glycogen
16
Q
If genes are not located in the nucleus, it is likely that they will…
A
self replicate, just as the chromosomes do if they are to be passed from one generation to the next, despite the fact that they are not in the nucleus
17
Q
What happens during the S phase of the cell cycle?
A
DNA is synthesized
18
Q
Is the cytoplasm split evenly during oogenesis?
A
no- the zygote that results from fertilization will receive the majority of cytoplasm; the polar body will have the same organelles + genetic material, but less cytoplasm
19
Q
Do macronuclei have an even distribution of DNA?
A
No, distribution is uneven during amniotic cell division
20
Q
What is the polar body?
A
a small cell that is the byproduct of oogenesis
21
Q
Macronuclei vs. Micronuclei
A
Macronuclei for somatic functions and gene expression
Micronuclei for reproduction and has genetic information (will contribute to phenotype)
22
Q
How to control timing of a gene?
A
Timing is controlled by specific regulatory elements, not necessarily the location of the antisense gene relative to the target gene.
23
Q
How would an anti-sense strand line up against an mRNA sequence?
A
in an antiparallel fashion with the sense molecule, meaning its 3′ end would line up with the 5′ end of its complement.
24
Q
An effective and efficient method for the delivery of an antisense gene could be:
A
infecting an embryo by a virus modified to carry the gene
25
How does cell differentiation occur?
Cells become different, distinct proteins
mRNA turnover is required for proper expression
26
Myoglobin
holds oxygen in the muscles and organs
27
Control of heart rate, muscle coordination, and appetite is maintained by
the brain stem, cerebellum, and hypothalamus, respectively.
28
What happens during vasodilation?
Greater than normal blood flow around the body, introducing more oxygen and nutrients
29
Where is pain percieved?
In the synapses
(not at a neuromuscular junction nor at the site of the stimulus)
30
Do prokaryotes contain ribosomes
Yes, but do not contain membrane bound organelles (nucleus, mitochondria, etc.)
31
Difference between anaphase of mitosis and meiosis I
During anaphase of mitosis, sister chromatids are pulled apart at the centromeres, each becoming an independent chromosome in the two diploid daughter cells.
During anaphase I of meiosis I, homologous pairs of chromosomes are separated into the two daughter cells. It is not until anaphase II of meiosis II that the centromere is split and the sister chromatids separate.
32
Synapsis
pairing of homologous chromosomes, and binding together
happens during meiosis I, but not mitosis
33
What are the causes of most spontaneous mutations?
DNA replication, lesions, or transposable genetic elements
34
Are inbred species likely to have deleterious recessive traits?
Yes, the chances of getting a pair of deleterious recessive genes increase enormously when the mate is a relative, because relatives are likely to have a similar genotype.
35
How does low blood pressure impact the glomerular filtration rate?
It decreases it, therefore allowing more time for reabsorption and decreasing the amount of filtrate in the urine.
36
What would happen if the heart stopped and the blood in the glomerular capillaries had no hydrostatic pressure?
fluid in the space around the glomerulus would flow back into the capillary bloodstream. This would occur because the protein-rich blood would be hypertonic with respect to the protein-poor fluid in the capsular space so that the fluid would flow down the osmotic gradient into the blood.
37
How will increasing blood pressure change the flow of fluid through the kidney system?
Increasing blood pressure should increase flow of fluid through the kidney system and decrease, rather than increase, water reabsorption
38
What determines resistance to blood?
The resistance to blood flow is primarily determined by the caliber of the small arteries, arterioles, and precapillary sphincters.
39
The sperm midpiece contains high levels of what?
mitochondria to increase sperm motility
40
Mutations
heritable changes in the sequence of the nucleic acid component of chromosomes
41
What is necessary for a protein to function properly?
for a protein to function properly, it must have a very specific three-dimensional structure. This three-dimensional structure of a protein is stabilized by covalent bonds and noncovalent interactions between different regions of the linear peptide.
42
What factors impact protein folding?
This three-dimensional structure can be disrupted by heating or by changing the pH.
43
albumin
the major osmoregulatory protein in the blood
44
How will changes in plasma albumin impact the osmotic balance?
An increase in plasma albumin will upset the osmotic balance because the blood will become hypertonic with respect to the tissue. Water will have to flow into the bloodstream to reestablish equilibrium.
One of the causes of edema, increased fluid in body tissues, is a decrease in the plasma protein level. This occurs, for instance, in starvation when the body is forced to use its albumin as an energy source. An increase in the plasma protein level would have the opposite effect: fluid would enter the bloodstream
45
Would an increase in the level of plasma aldosterone be expected to follow ingestion of excessive quantities of NaCl?
No; aldosterone causes Na+ reabsorption by the kidney tubules
Aldosterone, which is produced by the adrenal cortex, causes Na+ reabsorption by kidney tubules. Such a mechanism decreases Na+ levels in the urine. The steroid aldosterone does not cause Na+ secretion into the urine. Because ingestion of excessive NaCl would trigger Na+ secretion into the urine, plasma-aldosterone levels would not increase. Rather, the body would rely on those homeostatic mechanisms that excreted the excess Na+
46
Is the ability to produce ATP via ATP synthase is common to both bacterial and human cells?
Yes, both possess a membrane-embedded electron transport chain capable of generating a H+ gradient, which drives synthesis of ATP via ATP synthase. This ATP synthesis takes place on the plasma membrane of bacteria and on the inner mitochondrial membrane in human cells.
47
Vitamin D
stimulates calcium absorption through the small intestine and enhances effect of parathyroid hormone
48
What happens if you're deficient in parathyroid hormone
there would be a surplus of calcium because the bone matrix isn't being broken down
49
Osteoclasts
break down bone cells and release minerals (calcium)
increase blood calcium levels
50
parathyroid hormone
encourages osteoclast activity (break down bone and increase blood calcium)
detects when blood calcium is low
51
Vitamin C (bones)
required for the synthesis of bone matrix, and bone formation
52
Parathyroid hormone and calcatonin are...
antagonistic-- PTH encourages bone break down (osteoclast acvitity), calcatonin encourages bone formation (increase osteoblast activity)
53
which will kick in when blood calcium is low?
PTH
54
which will kick in when blood calcium is high?
calcitonin
55
Does aldosterone increase blood pressure or blood volume?
both!
56
How is the menstrual cycle regulated?
The hypothalamus exerts control over the pituitary hormones involved in menstruation by secreting hormone-releasing factors into the pituitary portal circulation. The gonadotropic hormones FSH and LH produced by the pituitary and the ovarian hormones estrogen and progesterone all have a role in regulating the human menstrual cycle. Therefore, close interaction among the hypothalamus, the pituitary, and the ovary is necessary for the human menstrual cycle.
57
Where does the transcription of DNA into RNA take place?
the nucleus
58
Where does the translation of RNA into protein take place?
the ribosomes
59
Where is skin derived? (mesoderm, ectoderm, endoderm)
epidermis from ectoderm
dermis from mesoderm
60
Ectoderm
the things that make you attractive. Skin (external apperance), and your brains (nervous tissue).
The additional thing to know is adrenal medulla
61
Mesoderm
"the means of getting around" - your bones & other organs/systems (heart and blood)
Also, the adrenal cortex.
62
Endoderm
Digestive tract organs/tract
Urinary System, Respiratory system, thyroid/parathyroid glands
63
Is glycolysis aerobic?
it can be, or it can function anaerobically
64
Do mitochondria have all the machinery for protein synthesis?
Yes (tRNA, ribosomes, etc)
65
What will happen to ATP if an artificial gradient allows protons to move through the mitochondrial membrane?
ATP will decrease because the gradient will be destroyed, there will be no stored energy, and the protons will be in equilibrium
remember, ATP synthase moves protons against the gradient
66
What type of ribosomes do bacteria and eukaryotes have?
large subunit of the bacterial ribosome: 50 S
large ribosomal subunit of eukaryotic cells: 60s
prokaryotes: 70S
Eukaryotes: 80S
66
What type of ribosomes do bacteria and eukaryotes have?
Bacteria: 70S
Eukaryotes: 80S
67
What will happen to ATP synthesis if the membrane becomes permeable to increased movement of K+ into the mitochondria?
It will decrease; an influx of another positively charged ion into the compartment would disrupt the electrochemical gradient responsible for the necessary flow of protons.
68
Where are the charged protons located in the gradient in the ETC?
In the intermembrane space
69
neurotransmitters
chemicals that are released at synapses; move across the synaptic cleft to the next neuron (a postsynaptic neuron). There they bind to specific receptors, causing changes in the electrical properties of target cells, which can cause postsynaptic effects. Work locally and their actions are very fast.
70
Hormones
are released directly into the blood and target specific regions of the body
71
steps of transmission of an impulse at a neuromuscular junction
The action potential of a neuron releases acetylcholine into the synaptic cleft which binds membrane bound receptors and activates ion channels
72
sliding filament model
According to this model, neuronal impulses cause the release of calcium from the sarcoplasmic reticulum within muscle cells. The calcium then binds to troponin, a molecule that along with tropomyosin, blocks the binding sites for myosin on actin molecules. Calcium binding to troponin causes a shift in the troponin/tropomyosin complex, revealing the binding site for myosin. Myosin then binds to actin, causing a conformational change in myosin that "cocks" the head of the myosin molecule and slides the actin filament relative to myosin. ATP binds to myosin, causing it to detach from actin and "recharge" (rebend again). If another binding site is available on actin, myosin will bind again, and slide the actin filament even further.
73
What happens in the kidneys during dehydration?
severe dehydration reduces the volume of filtrate moving through the nephrons. If fluid volume is too drastically reduced, the kidney will be unable to effectively do its job of filtering and maintaining homeostasis within bodily fluids
74
gall bladder
stores bile produced by the liver.
75
The major dissolved components of bile
breakdown products of hemoglobin such as bilirubin and bile salts.
The bile salts are amphipathic; that is, they have a hydophobic portion that is soluble only in fats and oils and a hydrophilic portion that is soluble in water. Bile salts allow dietary fats (and oils), which do not dissolve in the watery digestive juices, to form an emulsion of tiny droplets dispersed in the digestive juices.
One end of a bile salt molecule associates with the fats and the other with the aqueous solution in the gut. The dispersion of fats in the aqueous digestive juices and aids digestion by making them available to digestive enzymes.
Since triglycerides are hydrophobic fats, bile would aid in their digestion
76
What are histones?
come together with DNA to form nucleosomes, the bead-like, primary structural elements of chromatin. Interactions among histone proteins in separate nucleosomes allow those nucleosomes to form the highly compacted 30-nm chromatin fibers.
77
How would histones be impacted by PTMs that alter the charge?
would affect their ability to condense DNA.
78
How do long bones grow?
Long bones grow via endochondral ossification, which requires cartilaginous growth plates at the ends of long bones, that thicken as cartilage and later become ossified.
79
Haversian canals
Tubes that contain blood vessels and nerves around narrow channels formed by lamellae
surround blood vessels and nerve fibers and communicate with osteocytes
80
What kinds of responses do B and T cells contribute to?
adaptive immune system; T cells regulate cell-mediated responses and B cells regulate humoral responses
81
How are exocrine factors transported?
ducts
82
how are endocrine factors transported?
the blood
83
how are autocrine and paracrine signals sent?
aracrine chemical messengers act on cells near the cell that secretes the messenger, and autocrine chemical messengers act on the same cell that secretes the messenger.
not taken up by blood
84
A greater amount of hemoglobin correlates to...
an increased ability of blood to uptake oxygen
85
How many rings does tryptophan have?
2; it contains an indole group
(histidines have imidazole group)
86
Which steps of the citric acid cycle create NADH?
Malate dehydrogenase, isocitrate dehydrogenase and α-Ketoglutarate dehydrogenase all generate NADH within the citric acid cycle.
87
Is K>1 exergonic or endergonic?
exergonic
88
Transformation
Transduction
Conjugation
Transformation is the process that transfers genetic material from the environment into bacteria.
Transduction is the process by which nucleic acids are transferred from viruses to cells.
Conjugation is the exchange of nucleic acids between bacteria.
89
Mixed competitors
bind to a location besides the active site
-noncompetitive inhibitors do not bind
90
What type of enzyme is lactase?
lactase breaks down lactose to glucose and galactose. Glycosidic linkages in disaccharides are cleaved via a hydrolysis reaction; therefore, lactase is classified as a hydrolase.
91
the appendix
a continuous structure with the colon
92
The inner membrane of a mitochondrion is analogous to the ______ of a prokaryote.
plasma membrane
93
Spleen functions
immune surveillance and blood storage + recycling old red blood cells
94
Sympathetic nervous system inhibits the following functions
peristalsis, secretion of digestive enzymes, nutrient delivery to muscles and organs (increased blood glucose and dilation of blood vessels)
95
Why is Ca2+ important in the neuronal membrane?
When an action potential reaches a nerve terminal it triggers the opening of Ca+ channels in the neuronal membrane. Because the extracellular concentration of Ca+ is greater than the intracellular Ca+ concentration, Ca+ flows into the nerve terminal. This triggers a series of events
96
Order of blood flow
arteries to capillaries to veins
ACV
97
What is the role of the kidneys?
To excrete nitrogenous waste products
98
Can a cell be arrested in G1 as well as G0?
Yes, G1 characterized by increased production of macronutrients + other cellular resources; it is kind of a checkpoint for interphase and a cell will not have to move towards mitotic division
99
What happens to the diaphragm during inspiration?
The diaphragm contracts and pulls downward, causing air to enter the lungs.
100
What happens to the intercostal rib muscles during inspiration?
They contract to expand the rib cage
101
What causes glucocorticoid secretion by the adrenal cortex
stress
102
blood pressure highest to lowest (cardiac system)
heart --> arteries --> arterioles --> capillaries --> veins
103
What is primarily occurring in the colon?
absorption of water
104
Adaptive Radiation (Darwin's finches)
Adaptive radiation involves the divergence of one species into multiple species over time, which can occur when subgroups of the original species are separated or isolated in different environments so that these subgroups evolve independently of one another.
105
Is the pulmonary artery oxygenated?
Does it have CO2?
How does its pH compare to aortic blood?
Yes, think of it as essentially the same as venous blood. It has passed through the tissues of the body where it has given up oxygen and taken on CO2.
It has been pumped through the right side of the heart from the veins and headed for the lung where it will become oxygenated and will dispose of its CO2 load.
Since it carries CO2, it has a lower pH than aortic blood
106
Is the left ventricle thinner or thicker than the right?
Thicker and induces higher pressure to pump blood to rest of body
107
Where are proteolytic enzymes produced?
the pancreas!
they are then released into the small intestine where they are converted to their active forms of trypsin, chymotrypsin, and carboxypeptidase.
108
What is the pathway of a nerve impulse during the response from a knee jerk reflex
sensory neurons to motor neurons
109
Can viruses reproduce via fission?
No; they reproduce by replicating within the host cell. Bacteria reproduce by fission
110
Endocytosis
process of engulfing extracellular material
111
Neurons secrete ___ by ___.
neurotransmitters; exocytosis
112
Oxidative metabolism requires:
oxygen and acetyl CoA
113
What is required for glucose to become pyruvate in the glycolytic pathway?
the investment of 2 ATP
114
Where is epinephrine secreted from?
the adrenal medulla
115
Calcium, phosphate, and hydroxyl groups are all present in...
the salt present in human bone
116
stress axis would be aligned with...
hpa axis where hypothalamus secretes corticotropin releasing hormone, anterior pituitary releases ACTH and adrenal cortex releases cortisol
117
The reproductive axis
hypothalamus secretes gonadotropin releasing hormone which tells the pituitary gland to release LH and FSH to signal gonads to produce their respective hormones
118
Ligase
joins okazaki fragments
119
primase
lays down RNA primer on lagging strand; is complementary to DNA strand
120
topoisomerase
prevents recoiling of DNA strands during replication by preventing supercoiling
121
Protease function
cleave peptide bonds using water
122
can prokaryotes be alternately spliced?
no- alternative splicing (exons from the same gene are joined in different combinations, leading to different, but related, mRNA transcripts to increase protein variability) is exclusive to eukaryotes
123
secondary active transport
use energy stored in gradients produced by primary active transport
124
What happens when acetylation is increased?
Transcription increases and gene expression is active
decreases positive charge and weakens interaction between histidine and DNA
125
What happens when fasting?
At first, gluconeogenesis and glycogenolysis will be activated, then will use fatty acid oxidation and ketogenesis
126
Adrenal medulla secretes ____ in response to ____ and impacts the _______ nervous system
epinephrine and norepinephrine; stress; sympathetic
127
which form of NAD(H) feeds into etc?
NADH; the reduced form is needed here
128
What energy metabolism process will occur during hypoxia?
lactic acid fermentation will consume NADH (donates electrons to pyruvate to form lactate) and generate NAD+ for use in glycolysis to increase energy production
129
restriction enzymes can only recognize a binding sequence if it is...
complementary/palindromic; the complement of the sequence is the same as reading the strand in reverse
130
ETC complexes
NADH dehydrogenase
Succinate Dehydrogenase
Cytochrome c
Cytochrome c oxidase
131
Imprinted genes
parent-specific based on inherited epigenetic modifications
ex. methylations
132
Where does protein synthesis begin?
at the N terminus, one on end of the molecule
133
What will happen if a person has excess unabsorbed fats in their intestines?
sodium absorption (stimulated by short chain fatty acids) and bile salt resorption will decrease
excess solutes that are not absorbed increase osmotic pressure, causing increased fluid in the intestines (diarrhea)
134
Conservation
ex. knowing that two different shaped cups have the same amount in them
develops from 7-11 years (concrete operational)
135
Sympathetic nervous system
increases blood pressure and heart rate and sends blood to heart, muscles, and brain
136
α and β distinguish between:
epimers at an anomeric carbon (is OH pointing up or down; this C is attached to the oxygen in the ring)
137
What does higher osmotic pressure indicate?
that more water wants to enter the solution; calculate a solution's concentration (ions x conc)
138
What is a phosphodiester bond (hold together DNA) composed of?
P-O
139
What is a peptide bond (hold together amino acids) composed of?
C-N
140
What are glycosidic bonds composed of?
C-O-C
141
How to test a competitive inhibitor
Competitive inhibitors bind at the active site of the enzyme and can be overcome with high substrate concentration.
They characteristically increase Km (lower affinity) because a higher [substrate] is needed to reach 1/2 maximal velocity due to occupation of the enzyme active sites by the inhibitors.
Vmax is unaltered in a competitive inhibitor system (Vmax would only be altered in this system if the [enzyme] changes), you know you must keep enzyme concentration steady.
142
What is the effect of a reducing agent on a protein?
disrupt disulfide bonds
143
What is required for an uncompetitive inhibitor to bind?
substrate must be already bound to active sit
144
Where are signal sequences found?
In proteins that are headed for the secretory pathway ( to be removed from the cell or into cell membranes )
145
Where does dimerization occur?
Dimerization occurs in the cytosol (hydrophilic)
occurs due to hydrophobic interactions
146
How are different isoforms created?
from different alternative splicing to create different combinations of exons
147
cDNA
DNA that has been reverse transcribed from RNA
148
Reverse transcriptase
RNA from DNA
149
Is acetyl coa gluconeogenic?
no it is ketogenic; cannot be converted into glucose
150
Are lactate and glycerol gluconeogenic precursors?
Yes, lactate from cori cycle and glycerol from converting DHAP with G3PDH enzyme
oxaloacetate is also a substrate
151
acetyl groups
Add a carbonyl with a methyl (2 C, 3 H, 1 O)
152
What types of molecules are good for analyzing gene expression?
RNA, Protein
DNA give gene info, but not expression info
153
where does fatty acid oxidation take place?
the mitochondria
154
As blood passes through actively contracting skeletal muscle tissue, the affinity of hemoglobin for oxygen in the muscle tissue:
decrease with a decrease in plasma pH, and during prolonged exercise, anaerobic respiration would decrease the plasma pH.
155
What is the APE site of amino acids?
protein translation, aminoacyl transferase functions to transfer the tRNA originally bound at the A (amino acid) site to the P (peptide) site and later to the E (exit) site of the ribosome
156
RT-PCR
a molecular technique that measures mRNA levels of specific protein.
157
Is water excreted through the lungs?
yes, lungs use water to humidify the air that enters the body.
158
Will a phosphotransferase impact the isoelectric point?
yes, The addition of phospho group adds a negative charge and thus decreases isoelectric point
159
What type of intercellular junction is present between endothelial cells of brain capillaries results in the blood–brain barrier?
Tight junctions prevent the movement of solutes within the space between adjacent cells. In blood capillaries, neighboring endothelial cells form tight junctions with one another to restrict the diffusion of harmful substances and large molecules into the interstitial fluid surrounding the brain
