Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT Biological Sciences > Biology > Flashcards

Biology Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
1
Q

What is the F factor plasmid?

A

The fertility or F factor that contains special genes for the pilus to form during conjugation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the limit of resolution of a light microscope?

A

200 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Virus structures are:

a. smaller than all known eukaryotic cells
b. approximately the size of a coccus bacterium
c. larger than a human red blood corpuscle
d. larger than all known bacteriophages

A

Virus structures are:

smaller than all known eukaryotic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Can eukaryotic cells be seen with a light microscope?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a bacteriophage? Is it smaller or larger than bacteria?

A

A bacteriophage is a virus in baceria. They must be smaller than bacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Glucose is labeled with 14C and followed as it is broken down to produce CO2, H2O, and ATP in a mammalian liver cell. In theory during this process the label will be detectable:

A. In the mitochondria only
B. First in the nucleus, then in the mitochondria
C. First in the mitochondria, then on the ribosomes
D. First in the cytoplasm, then in the mitochondria

A

First in the cytoplasm, then in the mitochondria

Breakdown of glucose proceeds first by glycolysis, then by oxidation in the citric acid (Krebs or tricarboxylic acid) cycle. Enzymes for glycolysis are in the cytoplasm, and enzymes for the oxidation of citric acid arein the matrix of the mitochondria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Most fungal spores are:

a. Metabolically active and diploid
b. Metabolically inactive and haploid
c. Relatively sensitive to environmental changes
d. encased in a porous nuclear membrane

A

b.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The saponification product is acidified to convert:

a. An ester into an acid
b. An acid into a salt
c. A salt into an acid
d. An ester into a salt

A

c. A salt into an acid

Saponification is the hydrolysis of an ester using aqueous hydroxide. The saponification reaction product is a carboxylate salt which is then acidified to the corresponding carboxylic acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Inflamation of the lungs in mammals is accomplished by:

A

Negative pressure pumping action.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does aldosterone do?

A
  • Produced by adrenal cortex
  • Causes Na+ reabsorption by the kidney
  • Decreases Na+ levels in urine
  • Ingestion of excess NaCl would trigger Na+ secretion into the urine, plasma-aldosterone levels would not increase. The body would rely on homeostatic mechanisms that excreted the excess Na+.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

HIV is a retrovirus, an RNA virus that can insert itself into the human genome. This virus can reproduce in host cells because it contains _____.

A

Reverse Transcriptase. (converts its RNA to DNA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The sequence of events in the human menstrual cycle involves close interaction among which organs?

A

Hypothalamus-pituitary-ovary

  • Hypothalamus exerts control over the pituitary hormones involved in menstruation by secreting hormone-releasing factors into the pituitary portal circulation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

If Cholesterol is a precursor of steriod hormones, it is a precursor of which of the following hormones?

  • Insulin
  • Gastrin
  • Thyroxin
  • Estrogen
A

Estrogen- estrogen is a steroid hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where to ingested fats collect in the small intenstine?

A

In the lacteals- for transport to venous (portal) circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

By what process does breakdown of glucose occur?

A

By glycolysis, then by oxidation in the citric acid cycle (Krebs or tricarboxylic acid). Enzymes for glycolysis are in the cytoplasm and enzymes for the citric acid cycle are in the matrix of the mitochondria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A resident of a famine area who appears undernourished and extremely emaciated has eaten only starch for three months. A urine analysis shows that a large amount of nitrogen is being excreted. This is most likely evidence of:

A

Breakdown of the body’s own structural proteins to provide energy.

In starvation the body uses up its stores of carbs and lipids, then begins to break down body proteins for metabolic energy. A byproduct of the metabolism of the amino acids from protein is nitrogen. The reason animals have kidneys is to provide a way of eliminating nitrogeneous waste products.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the purpose of introducing small air bubbles into a distillation flask?

A

This prevents superheating of the liquid to be distilled. (provided by a biling chip or ebulliator). The air bubbles break the surface tension of the liquid being heated and prevent superheating and bumping.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is phosphorylation?

A

The addition of high-energy phosphate groups by a kinase to another protein. A molecule such as ATP (adensoine triphosphate) donates the phosphate group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

____ and ____ regulate blood levels of calcium

A

Parathyroid hormone and calcitonin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Calcitonin ___ osteoporosis

A

Calcitonin inhibits osteoporosis by taking calcium out of the blood and into the bone while preventing the loss of calcium from bone into the blood. High levels of calcium in the blood should stimulate this process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Parathyroid hormone is ___ by high levels of calcium.

A

parathyroid hormone is inhibited by high levels of calcium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Calcitonin puts/gets rid of calcium in bone.

Parathyroid hormone puts/gets rid of calcium in bone.

A

Calcitonin puts calcium in bone.

Parathyroid hormone gets rid of calcium in bone.

(Calcitonin-in, parathyro_id_-rid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In eukaryotes, oxidative phosphorylation occurs in the ___.

A

Mitochondrion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In eukaryotes, oxidative phoxphorylation occurs in the mitochondrion. The analogous structure used by bacteria to carry out oxidative phosphorylation is the ___.

A

Plasma membrane

Inner membrane of a mitochondrion is analogous to the plasma membrane of a prokaryote. The enzymes for oxidative phosphorylation are embedded in the inner membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the endosymbiotic theory?

A

Mitochondria are descendents of prokaryotes that were engulfed by endocytosis into a vesicle lined with a membrane derived from the cell membrane of the eukaryote host. This is the outer membrane. The inner membrane of the mitochondrion is the plasma membrane of the endosymbiotic prokaryote.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In which organelle of a eukaryotic cell is the pyrimidine uracil, as part of uridine triphosphate (UTP) incorporated into nucleic acid?

A

The nucleus.

Uridine is found in RNA, but not DNA. Uridine is incorporated into RNA in the nucleus where transcription of DNA into RNA takes place. RNA is manufactured in the nucleus from a DNA template.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the renin-angiotensin pathway?

A
  • Kidney (JGA cells) release renin
  • triggers formation of angiotensin II
  • stimulates aldosterone release
  • Raises blood presssure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does aldosterone do to blood pressure?

A
  • Aldosterone (mineralocorticoid) released by adrenal glands
  • Causes distal tubules in kidney to reabsorb more Na+
  • Causes more water reabsorption
  • Increase BP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does ADH affect BP?

(Where is it made and stored?)

A
  • Made in hypothalamus, stored in pituitary
  • Causes more water reabsorption in kidney tubules
  • Raises BP
  • Also causes vasoconstriction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is ANP? How does it affect BP?

A
  • Atrial natriuretic peptide
  • Antagonizes aldosterone
  • Causes kidney to excrete more NaP and water
  • Causes vasodilation
  • Helps lower BP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does blood plasma mainly consist of?

A

Na+ and Cl-

(Inside cells is mainly K+ and Hydrogen phosphate ions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does aldosterone regulate?

A
  • causes reabsorption of Na+
  • Secretion of K+
  • Increase blood osmolarity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is PTH?

A
  • Parathyroid hormone
  • Regulates calcium and phosphate
  • more Ca2+ reabsorption in kidney tubules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How is blood pH kept constant?

A
  • bicarbonate buffer system (blood and extracellular fluid)
    • CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-
    • Breathing out CO2 decreases acidity of blood
    • Reabsorption of bicarbonate (HCO3-) makes blood more basic
  • Phosphate buffer system (inside cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What nitrogenous wastes do the kidneys remove?

A
  • Urine (concentrated urea in water, with some salt)
  • Urea (harmless form of ammonia, nitrogenous waste)
  • Amino acids → Ammonia → Urea → peed out
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Kidney structure

  • Outer shell
  • Inner shell
  • Functional unit
A
  • Outer = cortex (contains convoluted tubules)
  • Inner = medulla (contains loop of henle)
  • Functional unit = Nephron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does the nephron consist of?

A
  • Glomerulus
  • Bowman’s capsule
  • Proximal tubule
  • Loop of Henle
  • Distal tubule
  • Collecting duct (shared by multiple nephrons)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the glomerulus?

A
  • ball of fenestrated capillaries
  • Urea + anything small in blood filters through
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is bowman’s capsule?

A

The cup/capsule that surrounds the glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the Proximal Tubule? What is its function?

A
  • Convoluted tubule on the side of the bowman’s capsule
  • Major site for reabsorption (all nutrient, most salts, water) and secretion of waste (except K+)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the loop of Henle? Parts? Function of parts?

A
  • U shaped loop that dips into the renal medulla
  • Countercurrent multiplier mechanism occurs here
  • Descending limb: H2O reabsorption by osmosis (not salt permeable)
  • Bottom of U: most concentrated
  • Ascending limb: salt reabsorption (not H2O permeable)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the distal tubule? function?

A
  • Convoluted tubule on the side of the collecting duct
  • Hormone-controlled
  • Reabsorption of salts and water
  • Aldosterone-controlled secretion of K+
  • PTH causes reabsorption of Ca2+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the collecting duct? function?

A
  • The distal tubules of many nephrons drain here
  • ADH-controlled reabsorption of water
  • Hormone-controlled reabsorption/secretion of salts
  • Concentrates urine using the osmotic gradient established by the Loop of Henle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

How does glomerular filtration occur?

A
  • Powered by hydrostatic pressure
  • Both good and bad stuff pass through
  • Good: nutrients
  • Bad: urea (creatinine and uric acid too)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Secretion and reabsorption of solutes in kidneys

A
  • PCT: reabsorbs nutrients and ions
  • Loop of Henle: reabsorbs water and salt
  • DCT: selectively reabsorbs/secretes based on hormonal control
  • Collecting duct: reabsorbs water to concentrate urine if ADH is present
  • regulate bloo dpH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

How is uring concentrated?

A

Concentrated by the collecting duct.

  • Loop of henle has high osmolarity at the bottom, which pulls water out of urine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What does the countercurrent multiplier mechanism do?

A
  • Creates an osmotic gradient down the loop of Henle, used by the collecting duct to concentrate urine
  • NaCl pump on ascending limb creates this gradient
  • Countercurrent:
    • Descending limb: water flows out of filtrate
    • Ascending limb: salt flows out of filtrate
  • Multiplier:
    • Gradient-producing power of each NaCl pump multiplies down the length of the looop of Henle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

How is urea recycled?

A

Urea at the bottom of collecting duct leaks out into interstitial fluid and back into the filtrate. Contributes to high osmolarity at the bottom of the loop of henle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

How is urine stored and eliminated?

A
  • Collecting ducts drain into ureter
  • Ureters drain into bladder
  • Bladder stores urine
    • special epithelium can squish to accomodate large amounts of urine
  • Urine peed out through urethra
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are enzymes?

What are important biological reactions that use enzymes?

A
  • Enzymes are catalysts (increase rate of rxn, does not get used up)
  • Biological Reactions:
    • metabolism
    • DNA and RNA synthess
    • Protein synthesis
    • Digestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

How do enzymes work?

A
  • Decrease the activation energy (Ea) of a reaction by lowering the energy of the transition state
  • increase rate constant k (rate = k[A][B])
  • Do not change Keq
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Do enzymes affect kinematics or thermodynamics of a reaction?

A

Kinematics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are enzymes made up of?

A
  • Protein (most common)
  • RNA (ex. ribosome)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

4 levels of enzyme structure

A
  • Primary: sequence of protein or RNA
  • Secondary: H-bonding in backbone
  • Tertiary: 3-D structure (-R group interactions)
  • Quaternary: more than 1 chain involved (dimers, trimers, tetramers, oligomers)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

How are enzymes denatured?

A

heat or extreme pH (alter structure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Feedback inhibition in enzyme activity

A
  • Product of a pathway inhibits the pathway
  • ex. hexokinase (first enz in glycolysis) is inhibited by its product glucose-6-phosphate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is competitive inhibition?

A
  • Inhibitor competes with substrate for binding to active site
  • Increase amt of substrate needed for maximum rate
  • Doesn’t change maximum rate
  • Can be overcome by providing more substrate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is non-competitive inhibition?

A
  • Inhibitor binds to an allosteric site on the enzyme to deactivate it
  • Substrate can stilla ccess active site, but enzyme can no longer catalyze
  • Decreases the maximum rate
  • Doesn’t change amount of substrate to achieve maximum rate
  • Can’t be overcome by adding more substrate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

2 basic parts of metabolism?

another name for it?

A
  • Catabolism (breaking down stuff for energy)
  • Anabolism (using energy to build stuff for storage)
  • Also called “cellular respiration”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What are steps of aerobic metabolism?

A

Needs O2

  • Glycolysis
  • Oxidative decarboxylation
  • Krebs cycle
  • Electron transport chain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Steps of anaerobic metabolism?

A

Don’t need O2

  • Glycolysis
  • Alcohol or lactic acid fermentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Aerobic metabolism of glucose

A
  • 36 ATP produced per glucose
  • C6H12O6 + 6O2 → 6CO2 + 6H2O
    • ​CO2 produced by Krebs cycle
    • H2O produced by electron txp chain
    • Glucose components end up as CO2
    • O2 breathed in ends up as water
    • Metabolite (glucose) is completely oxidized
  • Energy is released when electrons pass from glucose to molecular O2 (ETC harnesses this energy)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

How many ATPs are produced per glucose in aerobic metabolism?

A

36

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Anaerobic metabolism of glucose?

  • How many ATP produced per glucose?
A
  • Partial oxidation of metabolite (glucose) to pyruvate
  • 2 ATP per glucose
  • Pyruvate reduced to alcohol or lactate
  • Bacteria reduce pyruvate to alcohol in alcohol fermentation
  • Humans reduce pyruvate to lactate in lactic acid fermentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

In Anaerobic metabolism, what do bacteria and humans reduce pyruvate to?

A
  • Bacteria: reduce pyruvate to alcohol in alcohol fermentation
  • Humans: reduce pyruvate to lactate in lactic acid fermentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What does glycolysis do?

Location?

Occurs in aerobic or anaerobic conditions?

Inhibited by ___?

A
  • Converts glucose (6C) to 2 pyruvates (3C)
  • Location: cytosol
  • 2 net ATP for every glucose (2 input, 4 output)
  • Occurs in aerobic and anaerobic conditions
  • Inhibited by ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is aerobic decarboxylation?

Location?

A
  • pyruvate (3C) → acetyl group (2C)
  • 1 NADH made for every pyruvate
  • Only w/ oxygen
  • Acetyl group attaches to Coenzyme A to make acetyl CoA
  • Location: mitochondrial matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is anaerobic fermentation?

Location?

Purpose?

A
  • Redox rxn: reduce pyruvate, oxidize NADH
  • 1 NAD+ made : 1 pyruvate used
  • Alcohol fermentation: pyruvate reduced to ethanol
  • Lactic acid fermentation: pyruvate reduced to lactate
  • Location: cytosol
  • Purpose: regenerate NAD+ (needed for glycolysis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Krebs Cycle

  • Location
  • Reactants/Products
  • Other names
  • Inhibited by ___
A
  • Location: mitochondrial matrix
  • For 1 acetyl CoA input:
    • 3 NADH made
    • 1 FADH2 made
    • 1 ATP (GTP) made
  • Coenzyme A regenerated
  • Other names: Krebs cycle, TCA, tricarboxylic acid cycle, citric acid cycle
  • Inhibited by: ATP and NADH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Electron Transport Chain and Oxidative Phosphorylation

  • Location
  • Input
A
  • Location: cristae (inner mitochondrial membrane)
  • Input NADH
  • Proton gradient
  • ETC: redox reactions
    • NADH oxidized to NAD+, O2 reduced to H2O
    • Electrons pass from NADH to FMN to Coenzyme Q, iron sulfur complexes, and cytochromes (cytochrome b, c, and aa3) before reducing oxygen
    • NADH is highest in energy, O2 is lowest
    • Energy is released
    • Proton gradient is generated- drives ATP synthase to make ATP (oxidative phosphorylation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Proton gradient in ETC

A
  • Energy released from passing electrons down the ETC is used to pump protons in intermembrane space of mitochondria
  • H+ concentration- establishes proton gradient
  • H+ wants to migrate down the proton gradient (from intermembrane space back into matrix) but can only do this by going through the ATP synthase
  • ATP synthase harnesses the energy of falling protons to convert ADP to ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is ETC inhibited by?

A

Certain antibiotics, cyanide, azide, carbon monoxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Fat metabolism

  • Where does it occur?
  • How?
A
  • Beta-oxidation occurs in matrix of mitochondria
  • Ester hydrolysis in the cytosol
  • Fatty esters gets hydrolyzed into free fatty acids by lipases
  • w/ ATP, fatty acid is activated by CoA (into a thioester)
  • Beta-oxidation breaks down the fatty-CoA to make acetyl CoA
    • also makes FADH2 and NADH
  • Acetyl CoA feeds into the Krebs cycle
  • FADH2 and NADH feed into the ETC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

T/F: Fats give more energy than any other food source

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Protein metabolism

  • How are proteins broken down?
A
  • Proteins broken down into amino acids by peptidases
  • N in the amino acid is converted to urea
    • or uric acid in desert animals, birds, and reptiles
  • C in amino acid is converted to pyruvate or acetyl-CoA (or other intermediates)
  • C products from amino acid metabolisms can either feed into the kreb cycle or be starting material for gluconeogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

DNA strands are parallel/antiparallel

A

DNA strands are antiparallel (one goes from 5’-3’, the other goes from 3’-5’)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

DNA composition?

A

Purine/Pyrimidine Base, sugar, phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Nucleotide

Nucleoside

A
  • Nucleotide = Base (Adenine, Guanine, Thymine, Cytosine) + sugar + phosphate
  • Nucleoside = base + sugar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Purines and Pyrimidines

A
  • Purines (A, G) - 2 rings
  • Pyrimidines (T, C) - 1 ring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What makes DNA acidic?

A

Phosphate group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Base pairs (how many H bonds between each?)

A
  • A + T (2 bonds)
  • G + C (3 bonds)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

5’-ATGC-3’ is complementary to what?

A

5’-GCAT-3’ or 3’-TACG-5’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Steps of DNA replication

A
  1. Double stranded DNA separates/unwinds
    • DNA gyrase uncoils DNA ahead of replication fork
    • Helicase unwinds DNA at replication fork
    • Single-strand binding protein (SSB) keeps DNA unwound
  2. Make complementary DNA from 5’ to 3’
    • Primase lays down RNA primer
    • DNA polymerase makes complementary DNA
    • DNA synth occurs on both strands
    • leading strand- proceeds in direction of replication fork
    • lagging strand- proceeds in opposite direction of replication fork (contains okazaki fragments)
  3. RNA primers are replaced with DNA by a special DNA polymerase
    • DNA polymerase has proof-reading activity
    • Replication occurs during S phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

leading vs lagging strand

A

leading: occurs in diretion of replication fork
lagging: occurs in direction opposite to replication fork (contains Okazaki fragments)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

How is replication semi-conservative?

A
  • Heavy DNA is old DNA, light DNA is used for synthesis of new DNA
  • After 1 round of replication- all intermediate weight
  • After 2 rounds- both heavy and light DNA seen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

How is DNA repaired during replication?

A
  • Proofreading = 3’-5’ exonuclease activity
    • polymerase backs up and replaces w/ correct nucleotide
  • 5’-3’ activity allows polymerase to clear away short stretches of incorrect nucleotides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Mismatch repair?

A

Enzymes recognize incorrectly paired base-pairs and cuts out the stretch of DNA containing the mismatch. The polymerase re-ads the correct nucleotides in.

  • cuts out DNA w/o methylations (new DNA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Base-excision repair

A

Damaged base gets cut out, base’s sugar phosphate backbone gets cut out, a few nucleotides next to base get cut out. Polymerase remakes the cut out nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Nucleotide excision repair

A

damaged nucleotides get cut out and then polymerase replaces it.

  • like mismatch repair, but not for a mismatch
  • For damages like thymine dimers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Nick translation

A
  • 5’ → 3’ exonuclease activity coupled to polymerase activity
  • Polymerase chews off the bad nucleotides and then replaces them with new nucleotides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

SOS response in E. Coli

A
  • Too much DNA damage for normal repair to handle
  • Polymerase replicates over damaged DNA as if it were normal
  • Template error rates are high, but better than not replicating at all
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Restriction enzymes

A
  • Restriction enzymes (restriction endonucleases)
  • Cut ds DNA at palindrome DNA sequences
  • Some make sticky ends, which can hybridize
  • Some make blunt ends, which can’t hybridize
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Hybridization of DNA

A
  • aka annealing
  • DNA strands base pair with each other
  • Southern blotting- DNA probes are used to hybridize onto DNA fragments containing a target sequence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

Gene cloning

A
  1. Cut gene and plasmid w/ same restriction enzyme
  2. Hybridize, then seal DNA in plasmid w/ DNA ligase
  3. Insert recombinant plasmid into bacteri
  4. Replicate inside bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

PCR process?

A
  1. Denaturation: heat (90°C) to separate double stranded DNA template.
  2. Annealing: cool for primers to anneal to the now single stranded DNA template
  3. Elongation: use heat stable polymerase to extend the primers
  4. Repeat steps 1 to 3 for n cycles. This will amplify the original DNA template by 2n
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Where are the following:

  1. DNA
  2. Transcription
  3. RNA
  4. Translation
  5. Protein
A
  1. DNA- in the nucleus
  2. Transcription- inside the nucleus (DNA transcribed into mRNA)
  3. RNA- mRNAs get transported out of nucleus into cytoplasm
  4. Translation- ribosomes read off mRNAs to make proteins
  5. Proteins- synthesized by ribosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

What is a codon?

A
  • mRNA sequence of nucleotides that codes for amino acids
    • 3 nucleotides : 1 amino acid
  • Degenerate: more than 1 codons code for a given amino acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

What is an anticodon?

A

3 bases on the tip of the tRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

Missense codon?

Nonsense codon?

A
  • Missense codon: mutated codon that results in a different AA
  • Nonsense codon: mutated codon that results in something other than an AA (ex. stop codon)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Initiation and Termination codons

(function, codon sequences)

A
  • Start: AUG signals the start of transpation
  • Stop: UAG, UGA, UAA signals the end of translation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

mRNA composition and structure

  • Eukaryotic vs prokaryotic mRNA
A
  • “messenger” RNA
  • Product of transcription and template for translation
  • 5’ cap protects 5’ end from exonuclease degradation
  • polyA tail protects the 3’ end of the mRNA from exonuclease degradation
  • Eukaryotic: 5’ cap - nucleotides - 3’ poly A
  • Prokaryotic: don’t have 5’ cap or polyA tail
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

tRNA

A
  • Responsible for bringing in the correct amino acid during translation
  • The 3’ end of the tRNA attaches the amino acid via an ester linkage
  • Clover leaf structure with anticodon at the tip, and the AA at the 3’ tail
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

rRNA

A
  • Makes up ribosome
  • made of nucleotides
  • Highly structured
  • Contains active site for catalysis
  • Catalyzes peptide bond formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Mechanism of transcription?

A
  1. Chain initiation- RNA polymerase binds to promoter (TATA box) of the ds DNA. dsDNA opens up
  2. Chain elongation- nucleoside triphosphates (AUGCs) adds corresponding to the DNA template. no primer is required. RNA elongates
  3. Chain termination
    1. Intrinsic termination- specific sequences called termination sites create a stem-look structure on the RNA that causes the RNA to slip off the template
    2. Rho dependent termination- a protein called the rho factor travels along the RNA and bumps off the polymerase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Transcription factors

A
  • Proteins that bind to enhancers or silencers (DNA) to affect transcription
  • Enhancers increase transcription when bound by TF
  • Silencers decrease transcription when bound
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

What are operons?

A
  • Groups of genes whose transcription can be regulated by binding of either repressors or inducers onto the stretch of DNA on the operon called the operator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

Corepressor? Coinducer?

A
  • Co-repressor binds to target- the resulting complex becomes wither an active repressor or an inactive inducer
  • Co-inducer binds to a target to become an active inducer or an inactive repressor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

Transcription attenuation

A
  • works in the trp (tryptophan) operon
  • When tryptophan is scarse, transcription occurs normally
  • If there is excess tryptophan, transcription terminates prematurely
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

Roles of mRNA, tRNA, and rRNA in translation

A
  • mRNA contains codons that code for the peptide
  • tRNA contains the anticodon, and amino acid on the “tail”
  • rRNA forms the ribosome, catalyzes the formation of the peptide bond
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

Role and structure of ribosomes

A
  • Enzyme that catalyzes protein synthesis
  • Large and small subunit
  • Large subunit- peptidyl transfer reaction
  • Small subunit- recognizing mRNA and binds to Shine-Dalgarno sequence on mRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Protein is made from __ terminus to __ terminus

mRNA is read from __ to __

A

from N to C

(mRNA codons are read from 5’ to 3’)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

Mechanism of translation

A
  1. Initiation- form initiation complex, includes mRNA, initiator tRNA, tibosome. The initiation complex forms around the start codon (AUG), which is downstream of the Shine-Dalgarno sequence (Kozak for eukaryotes)
  2. Chain elongation- protein made from N to C terminus
    1. Binding: new tRNA enters A site, GTP and elongation factor required
    2. Peptidyl transfer: attachment of new amino acid tot eh existing chain in the P site
    3. Translocation: long tRNA in the P site gets kicked off (E site), and the tRNA in the A site, moves into the P site. A site is now empty and ready for the binding of a new aminoacyl-tRNA to a new start codon.
  3. Chain Termination- when a stop codon is encountered, protons called release factors, bound to GTP, come in and block the A site. peptide chain is cleaved from tRNA in the P site. Peptide chain calls off.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

Chromosomal proteins

A
  1. histones- responsible for compact packing and winding of chromosomal DNA. DNA winds itself around histone octamers
  2. All other non-histone proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

What is a telomere?

A

2 ends of the chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

What is a centromere?

A
  • Region on the chromosome, can be at the center or close to one of the ends.
  • After replication sister chromatids are attached at the centromere.
  • During mitosis spindle fibers are attached at the centromere and pulls the sister chromatids apart
118
Q

Difference between chromatin and chromosome?

A

Chromatin is the “stuff” chromosomes are made of

119
Q

How are enhancers/silencers different in eukaryotes and prokaryotes?

A
  • Eukaryotes: can be far away from promoter, can be upstream or downstream
120
Q

Do eukaryotes have operons? attenuation?

A

No

121
Q

How is cancer a failure of normal cellular controls?

A
  • Cancer cells continue to grow and divide
  • fail to respond to cellular controls and signals that halt growth in normal cells
  • They avoid apoptosis
  • Stimulate angiogenesis (new glood vessels to nourish cancer cells)
  • Cancer cells are immortal
  • Can mestastasize- break off then grow in another location
122
Q

What are oncogenes?

A
  • Genes that cause cancer when activated
  • Before activation, it is a harmless proto-oncogene
  • Classic example is the src
123
Q

What are tumor suppressors?

A
  • Products slow down or control cell division
  • Classic example is p53
124
Q

How is mRNA modified?

A
  • RNA splicing- introns are cut out, exons are kept and spliced together
  • Alternate splicing- differnet ways of cutting up RNA and rejoining the exons
  • 5’ capping and 3’ poly-A tail (protect RNA from degradation)
125
Q

What is a gene?

A

Stretch of DNA that codes for a trait. The gene codes for a protein, which acts to bring about a trait.

126
Q

Definition of Locus

A

Location of a gene on a chromosome

127
Q

T/F: all alleles of the same gene exist at the same locus

A

true

128
Q

Recessiveness

A
  • only expressed if both copies are present
129
Q

Co-dominance

A

For alleles A and B, the type AB makes both A and B antigens

130
Q

Incomplete domance

A

For alleles A and B, the genotype AB produces a phenotype in between A and B

(black chicken + white chicken = grey chicken)

131
Q

Definition of leakage

A

Gene flow from one species to another

132
Q

Definition of penetrance

A

The frequency that a genotype will result in the phenotype

133
Q

Definition of expressivity

A

To what degree a penetrant gene is expressed

(Constant expressivity means that if your genes for being smart manages to penetrate, then your IQ is 120. Variable expressivity emans that your IQ may be somewhat lower or somewhat higher)

134
Q

Differences between mitosis and meiosis

A

Meiosis

  • Tetrad formation and cross over
  • Daughter cells different from parent
  • Haploid (n) daughter cells
  • 2 divisions
  • 4 sperm or 1 egg (w/ polar bodies)

Mitosis

  • No tetrad
  • Daughter cells identical to parent cell
  • Diploid (2n) daughter cells
  • 1 division involved
  • 2 daughter cells
135
Q

Steps of Meiosis

A
  1. Prophase I, Metaphase I, Anaphase I, Telophase I
  2. Prophase II, Metaphase II, Anaphase II, Telphase II
136
Q

Steps of Mitosis

A
137
Q

Independent assortment

A
  • Generates genetic variation
  • Shuffles chromosomes from mom and dad, and places only 1 copy of each into the gamete
  • Occurs in metaphase I, when homologous chromosomes pair up along the metaphase line (some of moms on left, some randomly on right, same for dad’s)
138
Q

Linkage

A
  • Genes are more linked if they are physically closer
  • When genes are further apart, crossing over makes them less linked
139
Q

2 processes that make up recombination

A

independent assortment and crossing over

140
Q

Crossing over

  • When does it occur?
  • Where does it occur?
A
  • occurs during prophase I
  • site is the chiasma (possible because of pairing of homologous chromosomes called the tetrad, formed by synapsis)
  • single crossovers result in genetic recombination
  • double crossovers- may or may not result in genetic recombination
141
Q

Sex-linked genes

A
  • Genes for the characteristic is on the X chromosome
  • very few genes are on the Y chromosome
142
Q

Cytoplasmic inheritance

A

Inheritance of things other than genomic DNA, such as cellular organelles (ex. mitochondria)

143
Q

Types of Mutations

A
  1. Random mutation: random change in DNA sequence
  2. Translational error
  3. Transcription error
  4. Base substitution
  5. Inversion: stretch of DNA breaks off, then reattaches in the opposite orientation
  6. Addition/Insertion of extra base
  7. Deletion of base
  8. frameshift mutation- caused by single addition/insertion
  9. Translocation: stretch of DNA breaks off ad reattaches somewhere else
  10. Mispairing: A not with T, or G not pairing with C
144
Q

What are inborn errors of metabolism?

A

Genetic diseases resulting in faulty metabolism.

ex. PKU (Phenylketonuria)- people can’t metabolize phenylalanine

145
Q

Mutagen vs carcinogen?

A
  • Mutagen causes mutation
  • Carcinogen causes a mutation that causes cancer
  • Carcinogens are almost always mutagens
  • Not all mutagens are carcinogens
146
Q

Hardy-Weinberg principle

A

p+q=1

p2+2pq+q2=1

147
Q

5 assumptions of Hardy-Weinberg

A
  1. Infinitely large population (no genetic drift)
  2. No mutation
  3. No migration
  4. Random mating
  5. No natural selection
148
Q

What is a test cross?

A

If you have something with dominant phenotype, it could be Aa or AA. To find out, cross with the homozygous recessive aa. If Aa, half the offspring will express recessive phenotype. If AA, no offspring will express the recessive phenotype.

149
Q

Back cross

A

mating between the offspring and the parent = preserve parental genotype

150
Q

Fungi

  • What are they made of?
  • What are cell walls made of?
  • Examples?
A
  • made of hyphae filaments
  • parasitic hyphae = haustoria
  • mass of hyphae = mycelium
  • cell walls made of chitin
  • heterotrophs- parasites of saprobes
  • yeast molds and mushrooms are fungi
151
Q

What are lichens? mycorrhizae?

A
  • lichens = fungi + algae
    • algae provides food, fungi provides water and protection
  • Mycorrhizae = fungi + plant roots
    • plant provides food, fungi provides more absorption surface area
152
Q

Fungi life cycle

  • secual or asexual?
A
  • can be sexual or asexual
  • reproduce via spores or mycelial fragmentation
  • most fungi have a haploid and diploid stage of life cycle
153
Q

Virus structure

  • major components
  • smaller or larger than bacteria
  • are there organelles? nucleus?
A
  • Nucleic acid (DNA or RNA, ds or ss)
  • Protein coat covers nucleic acid
  • Some have envelope from host’s cell membrane
  • smaller than bacteria
  • lack organelles and nucleus
154
Q

Bacteriophage structure

A
155
Q

RNA viruses that convert their genome into DNA inside their host are called ____.

A

retroviruses

156
Q

Size of virus relative to bacteria and eukaryotic cells.

A

Viruses are roughly 100x smaller than bacteria, and 1000x smaller than eukaryotic cells.

157
Q

Can viruses replicate by themselves?

A
  • No
  • The host ribosomes make protein coats and polymerases
158
Q

Virus life cycle

A
  • Attach to host, penetrate cell membrane/wall, entry of viral genetic material
  • Use host to replicate viral components (Host provides ATP, amino acids, nucleotides)
  • Self-assembly and release of new viral particles
159
Q

Retrovirus life cycle

A
  • Retrovirus enters the host
  • Viral reverse transcriptase converts the viral RNA genome into ds DNA
  • Virally encoded enzyme (integrase) adds in the viral DNA into the host’s genome at a random place
160
Q

What is transduction?

steps?

A

Transfer of genetic material by viruses

  1. Virus infects cell, host DNA degraded into fragments, viral DNA takes over control
  2. Host DNA fragment gets packed into virus progeny by accident
  3. Virus progeny infects another cell, injects previous host’s DNA fragment
  4. Fragment enters cell, find its homologous counterpart, and crossover
161
Q

Do bacteria have a nucleus? spindles and asters?

Do bacteria have organelles?

A

No nuclear membrane (instead have an irregular nucleoid)

No spindles and asters (cytoskeleton pulls apart replicated DNA)

Lack typical eukaryotic organelles

162
Q

Shapes of bacteria

A
  • bacilli (rod)
  • spirilli (spiral)
  • cocci (spherical)
  • eubacteria (encounter every day)
  • archaea (inhabit extreme environments- high salt, temp, or chemicals)
163
Q

What is bacterial cell wall made up of? Plant cell wall? Fungi cell wall?

A

Bacterial cell wall is made of peptidoglycan.

Plant cell wall is made of cellulose

Fungi cell wall made of chitin

164
Q

Flagellar movement of bacteria

A
  • flagella made of flagellin
  • primary mechanism is rotation
165
Q

Obligate aerobe?

Obligate anaerobe?

Facultative anaerobe?

A
  • Obligate aerobe- must have oxygen for growth
  • Obligate anaerobe- dies when oxygen is present
  • Facultative anaerobe- doesn’t need oxygen for growth, but grows better with oxygen
166
Q

Symbiotic relationships

  • Parasitic
  • Mutualistic
  • Commensalistic
A
  • Parasitic- bacteria benefits at the expense of the host
  • Mutualistic- both bacteria and host benefits
  • Commensalistic- one benefits while the other has no effect
167
Q

A bacteria able to make a pillus is ___

A

F+

168
Q

Transformation of bacteria

A

Incorporation i nto bacterial genome of DNA fragments from external medium

  • When bacteria dies, it lyses and spills DNA fragments
169
Q

Prokaryotes regulate gene expression at the ____ level.

Eukaryotes regulate at other levels.

A

transcription level

170
Q

Transcription-translation coupling

A
  • In prokaryotes, translation occurs as the mRNA is being transcribed (no RNA processing in prokaryotes)
  • regularion by attenuation can occur for the Trp gene
    • full of Trp- translation occurs fast
    • starved of Trp- translation occurs slower
171
Q
  • What is nucleolus?
  • Location?
  • Function?
A
172
Q
  • function- transcribe ribosomal RNA (rRNA)
  • inside nucleus
A
173
Q

Mitochondria

  • What happens here?
  • How does it replicate?
  • Structure?
A
  • Site of ATP production: ATP synthase makes ATP from ADP by using proton gradient
  • Self-replication (has own DNA and ribosomes)
  • Structure:
    • inner membrane surrounds matrix
    • cristae = folds of inner membrane
    • Intermembrane space between outer and inner membranes
    • Intermembrane space is high in protons
174
Q

What are lysosomes?

A
  • vesicles containing hydrolytic enxymes
  • Digests food, and viral/bacterial particles
  • Things you want to digest gets into a vacuole by endocytosis or phagocytosis, then the vacuole fuses with the lysosome
175
Q

RER vs SER

(Rough vs. Smooth endoplasmic retuculum)

A
  • RER:
    • has ribosomes studded over it
    • deals with protein synth/folding/modification
  • SER:
    • no ribosomes
    • biosynthesis of lipids and steroids
    • metabolism of carbs and drugs
    • stores and regulates calcium
176
Q

Roles of ER in membrane biosynthesis

A
  • SER = makes lipids of the plasma membrane
  • RER = makes transmembrane proteins
    • carries them on its membrane
    • forms vesicles and bud off, fuses with the plasma membrane, transmembrane proteins now on plasma membrane
177
Q

Golgi apparatus

  • structure
  • function
A
  • looks like a stack of pancakes
  • modifies/secretes macromolecules for the cell
  • RER makes protein, Golgi modifies it, buds off golgi and secreted out of cell by exocytosis
  • Golgi can glycosylate proteins as well as modifying existing glycosylations
178
Q

Sodium Potassium Pump

A

3 Na+ out, 2 K+ in

(Negative resting potential)

179
Q
  • Gap junctions
  • Tight junctions
  • Desmosomes
A
  • Gap junctions- connects cells, allows stuff to flow between cells
  • Tight junctions- glues to cells together, forms an impermeable barrier
  • Desmosomes- connects 2 cells by linking their cytoskeleton, organized for mechanical strength, not impermeable
180
Q

What is a centriole?

A

microtubule organizing center

181
Q

Cell cycle

A

Interphase

  • G0 (no more replication or division), G1 (growth), S (synthesis, replicate DNA), G2 (growth)

Mitosis

  • **Prophase **= prepare (condense chromatin, break down nuclear membrane, assemble spindle, centrioles move)
  • **Metaphase **= middle
  • **Anaphase **= apart (sister chromatids pull apart)
  • Telophase = prophase in reverse
182
Q

Apoptosis

A

Programmed cell death

clean and healthy

No spilling of cell contents

Brought on by development or immune response

183
Q

Schwann cells vs. Oligodendrocytes?

A
  • Schwann cells = makes myelin sheath in the peripheral nervous system
  • Oligodendrocytes = makes myelin sheath around CNS axons
184
Q

How are neurotransmitterss released at the axon terminal?

A

Exocytosis of vesicles containing neurotransmitters. Triggered by calcium influx when action potential reaches axon terminal.

185
Q

Neurotransmitter molecules

A
  • Acetylcholine (ACh)
  • Norepinephrine (NE)
  • Dopamine
  • Serotonin
  • Histamine
  • ATP
186
Q

What is fatigue (with respect to neurons)

A

Continuous synaptic activity, depletion of neurotransmitters, fatigue

187
Q

Na+-K+ pump (how many in/out)

What leaks out?

Resting potential?

A

3 Na+ out, 2 K+ in

K+ leaks out

Resting potential = -70 mV

188
Q

Steps of an action potential

A
  1. Resting
  2. Depolarization (Na+ channels open, Na rushes inside)
  3. Repolarization (K+ channels open, Na+ channels close)
  4. Hyperpolarization (K+ channels don’t close fast enough, membrane potential drops below resting potential)
  5. Refractory period (Na-K pump works to reestablish the original resting state)
189
Q

Types of muscle

A
  • Striated (skeletal muscle, voluntary, stripes, multiple nuclei, shaped like long fibers)
  • Smooth (visceral, involuntary muscles, no stripes, 1 nucleus per cell, shaped like almonds)
  • Cardiac (heart muscles, involuntary, has stripes, 1 nucleus/cell, highly branched)
190
Q

Red vs White muscle (and pink)

A
  • Red Muscle = high endurance, slow
    • abundant mitochondria
    • Aerobic respiration predominant
    • Receive abunant O2 supply
    • High endurance, doesn’t tire easily
  • White muscle = fast, but fatigue easily
    • anaerobic resp (glycolysis) predominant
    • Short bursts of glycolysis- stores high amounts of glycogen
  • **Pink muscle **= intermediate
191
Q

Contractile elements of muscle

A
  • Actin = thin filament (troponin and tropomyosin)
  • Myosin = thick filament (myosin heads)
  • Cross bridge = myosin head binds to actin
192
Q

Sliding filament model

A
  • Cross bridge forms, myosin head bends (power stroke), causes actin to move in th edirection of power stroke (muscle contracts)
  • ATP not needed for power stroke, needed for detachment of myosin head to actin
  • ATP hydrolysis is needed for de-power stroke
193
Q

Rigor mortis

A

No ATP after a person dies, myosin heads can’t detach after power stroke, muscle remains in contracted position

194
Q

What are troponin and tropomyosin on muscle for?

A
  • Tropomyosin on actin blocks the myosin head from forming cross bridge
  • troponin move tropomyosin out of the way at high Ca2+ levels
  • Ca2+ binds to troponin, and troponin move tropomyosin
195
Q

What is the sarcoplasmic reticulum? T-tubules?

A
  • SR = smooth ER in muscle, stores calcium, releases them in response to AP
  • “terminal cisternae” where it meets T-tubules at the edge of the sarcomere
  • T-tubules: extension of the muscle cell membrane that runs deep into the muscle cell, so action potential can reach there
196
Q

Sarcomere structure

A
  • I band (thin filaments only), H-zone (thick filaments only), A band (thin and thick filaments)
  • M-line (line of myosin in the middle)
  • Z-line (zigzag lines on the sides, connects adjacent sarcomeres)
197
Q

Shapes of epithelial cells

Simple epithelium

Stratified epithelium

A
  • Squamous (flat), cuboidal (cube), columnar (column shaped)
  • Simple- single cell layer, for absorption, secretion, filtration, diffusion
    • Squamous: endothelium, capillary wall, alveolar wall
    • Cuboidal: gland ducts, kidney tubules
    • Columnar: stomach and gut
  • Stratified- 2 or more layers, good for protection against abrasion
    • Squamous: skin
    • Cuboidal/columnar: not common
198
Q

Endothelial cells

A

Lines the inside of organs and blood fessels (simple squamous epithelium)

199
Q

Connective tissue cells

A
  • Cells + extracellular matrix
  • Bone, fat, tendons, ligaments, cartilage, blood
    • osteoblasts make bone
    • fibroblasts make fats/tendons/ligaments/beneath epithelia
    • chondroblasts make cartilage
    • hematopoietic stem cells make blood
200
Q

-blast vs. -cyte

A
  • blast: stem cell actively producing matrix
  • cyte: mature cell, doing housekeeping
201
Q

Fiber types

A
  • Collagen- most common, very strong (found in dense connective tissue)
  • Elastic- can stretch
  • Reticular fibers- can branch and form nets (connective tissue)
202
Q

Skeletal vs Cardiac vs smooth

A
203
Q

Somatic vs Autonomic motor neurons

A

Somatic = controls skeletal muscles

Autonomic = sympathetic and parasympathetic divisions = controls involuntary muscles (smooth, cardiac)

204
Q

Neuromuscular junctions, motor end plates

A
205
Q

Sympathetic vs parasympathetic innervation

A
  • Sympathetic: fight or flight, heat beats faster, pupils dilate, raise blood rpessure, blood to muscles, less blood to gut
  • Parasympathetic: rest and digest, opposite of sympathetic
206
Q

___ hormones signal bone tissue to break down and release calcium

A

parathyroid

207
Q

Ligament vs. Tendon

A

Ligament = bone to bone, stabilize joints

Tendon = muscle to bone, anchors muscle

208
Q

Functions of osteoblasts and osteoclasts in bone growth

A

Length

  • Osteoblasts- add bone tissue at bone ends
  • Osteoclasts- remodel bone tissue, change shape

Diameter

  • Osteoblasts- add bone tissue to outside of bine
  • Osteoclasts- remove bone tissue from the inside of bone
209
Q

Digestive Activities of:

  1. Mouth
  2. Stomach
  3. Small Intestine
  4. Large Intestine
A
  1. Mouth- mechanical digestion (chewing), chemical (amylase and lipase)
  2. Stomach- Mechanical (churning), chemical (protease- pepsin)
  3. Small Intestine- chemicals from pancreas (amylase, protease, lipase, nuclease), Nutrient and water absorption
  4. Large Intestine- water absorption
210
Q

What is amylase? Where is it found?

A

Breaks down polysaccharides (starch and glycogen)

Found in mouth and small intestine

211
Q

What is peristalsis?

A

Squeezing stuff through a tube (esophagus/gut) by smooth muscle

212
Q

Stomach

  • What causes pH to be acidic?
  • What protects stomach?
A
  • Parietal cells secrete HCl, lower pH
  • Gastric juice = HCl + pepsin + hormones
  • Pepsin = protease that works best in acidic environment
  • Goblet cells secrete mucus lining that protects the stomach from the acid and self-digestion
213
Q

Liver

  • Function
  • Role in nutrient metabolism
  • Role in glucose regulation
A
  • Makes bile from cholesterol
  • Makes and stores glycogen form glucose
  • gluconeogenesis (from glycerol and amino acids)
  • Greaks down fats, makes cholesterol)
  • Stores vitamins (A, D, B12) and iron
  • metabolizes alcohol, removes ammonia in blood)
  • Blood glucose regulation
214
Q

How does liver regulate blood glucose levels if:

  • Blood sugar is too low
  • Blood sugar is too high
A
  • Too low- gluconeogenesis
  • Too high- glycogenesis
215
Q

Bile

function? location?

A
  • Stored in gall bladder
  • Emulsifying agent, beaks down large fat droplets into smaller droplets by forming micelles
  • Increases surface area of fat for lipase action
216
Q

Pancreas

  • What does it make?
  • Function?
A
  • Makes: amylase (starch), proteases, lipase (fat) ribonuclease (nucleic acid)
  • Makes HCO3- to neutralize the HCl from the stomach
  • Exocrine- flows into small intestine via duct (to duodenum)
217
Q

How does small intestine absorb fats?

A

Into lacteals

218
Q

Bacteria in large intestine

A

ferment undigested nutrients, make gas

Produce vitamin K (important for clotting)

219
Q

Breathing causes you to ___ heat.

A

Lose

220
Q

Negative pressure breathing

A
  • Diaphragm contracts, pulls downward, decreases pressure and sucks air into the lungs
  • Ribs expand, intercostal muscles help
221
Q

Differential pressure = ?

A

Difference between pressure inside lung (intrapulmonary) and outside lung (intrapleural)

222
Q

What causes the lung to collapse?

A

Surface tension causes the lung to collapse

Surfactants produced in the alveoli decreases surface tension, and helps alveoli to stay open.

223
Q

Path of blood going through the heart including valves

A
  1. Vena cava
  2. R atrium
  3. tricuspid valve
  4. R ventricle
  5. pulmonary valve
  6. pulmonary artery
  7. lung
  8. pulmonary vein
  9. L atrium
  10. Bicuspid (mitral) valve
  11. L ventricle
  12. Aortic valve
  13. Aorta
224
Q

T/F: Veins have valves

A

True: they have valve to prevent back flow of blood

225
Q

Thickness of blood vessels in order

A

artery > vein > arteriole > venule > capollaries

226
Q

Where is blood pressure highest? lowest?

A

Highest in arteries (aorta)

Lowest in veins (specifically vena cava)

227
Q

Blood-brain barrier?

A

sealing of clefts by tight junctions

228
Q

Do red blood cells have nuclei?

A

No nucleus- gives it a biconcave shape

229
Q

Where are RBCs made and destroyed? what is recycled/excreted?

A

RBCs are made from stem cells in bone marrow

Spleen destroys aged and damaged RBCs (also done in the liver and bone marrow)

Iron is recycled, heme is excreted as bilirubin in feces, protein (globin) is broken down

230
Q

ADH vs Aldosterone

A

ADH increases water reabsorption in the kidney

Aldosterone increases salt reabsorption, leads to increased water reabsorption in kidney

231
Q

Clotting

A
  • wound + platelets cause platelets to clump at the wound
  • Fibrinogen → fibrin (mesh that seals the clot)
232
Q

Hemoglobin protein

Hematocrit

A
  • Hemoglobin = 4(heme + globin)
    • heme binds iron, globin surrounds heme
    • 4 subunits = tetramer
  • Hematocrit = % volume of blood that is RBC (45%)
  • Millions of hemoglobin per RBC
233
Q

What does the hemoglobin oxygen binding curve look like?

A

Sigmoidal

(easier for additional oxygen to bind after the first one)

234
Q

T/F: CO binds hemoglobin tighter than O2

T/F: Fetal hemoglobin binds O2 less tightly than adult hemoglobin

A

True

False

235
Q

Major functions of lymphatic system

A
  • Equalizaiton of fluid distribution
  • Transport of proteins and large glycerides
  • Production of lymphocytes in immune reactions
  • Return of materials in the blood
  • Source of lymph
236
Q

How does lymphatic system txp proteins and large glycerides?

A
  • Fats are absorbed into the lacteals in the small intestine
  • lacteal = lymphatic capillary in the small intestine
  • Plasma protein that leaked into interstitial fluids get returned to the blood via the lymphatic system
237
Q

Where do T cells mature?

A

thymus

238
Q

What is the composition of lymph?

A

stuff that leaks out of capillaries- mostly water, plasma protein, chemicals, white blood cells

239
Q

Functions of the following cells:

  • macrophages
  • neutrophils
  • mast cells
  • natural killer cells
  • dendritic cells
A
  • macrophages: phagocytose pathogen, act as antigen presenting cell
  • neutrophils: phagocytose pathogen and destroys it
  • mast cells: release histamine during allergic response, bring about inflammation
  • **natural killer cells: **kills infected/abnormal cells
  • dendritic cells: the best antigen presenting cells
240
Q

T-lymphocytes

  • Where do they mature
  • types?
A
  • Matures in Thymus
  • cytotoxic T cell: regognize antigen on infected cell, signal for apoptosis
  • helper T cell: regocnize antigen, signal for activation of B cells, T cells and macrophages
241
Q

B-lymphocytes

  • where do they mature?
  • types?
A
  • Matures in Bone marrow
  • Plasma cells = secrete antibody
  • Memory cells = stick around in case the same antigen attacks in the future
242
Q

Antibody structure

A

2 heavy and 2 light chains are linked by disulfide bonds

243
Q

Function of the endocrine system

A

Makes hormones, secrete hormones into surrounding tissue fluids

244
Q
  • Endocrine
  • Exocrine
  • Autocrine
  • Paracrine
A
  • Endocrine- hormone, no duct, acts long distances
  • Exocrine- non-hormone secretions into ducts
  • Autocrine- local chemicals, act short distances on themselves
  • Paracrine- local chemicals, act short distances on other cells
245
Q

What does the hypothalamus release?

A

Releasing hormones for the pituitary, ADH, and oxytocin

246
Q

What does the pituitary make and store?

A

Makes: FLAT PEG, stores ADH and oxytocin

  • FSH: follicle stimulating hormone (stimulates ovary follicles to mature, testis to produce sperm)
  • LH: leutenizing hormone (triggers ovulation, stimulates testis to produce testosterone)
  • ACTH: AdrenoCorticoTropic Hormone (stimulates adrenal cortex to release glucocorticoids and mineralocorticoids)
  • TSH: thyroid stimulating hormone
  • PRL: Prolactin (stimulates breast to produce milk)
  • E: Endorphine
  • GH: growth hormone (growth of muscle, bone, burns fast)
247
Q

Pineal?

A

Endocrine gland that makes melatonin, which makes you sleepy at night

248
Q

What does the thyroid make?

A

thyroid hormones (increase metabolism, requires iodine)

Calcitonin (turns blood Ca2+ into bone)

249
Q

What does the parathyroid make?

A

Makes parathyroid hormone (PTH) which increases blood Ca2+

250
Q

What does the thymus do?

A

makes thymus hormones, stimulates T cells to develop

251
Q

What does the adrenal gland make?

A
  • Epi and norepi (fight or flight)
  • Mineralocorticoids (aldosterone) - increase Na+ and water retention, raises blood rpessure
  • Glucocorticoids (cortisol) - stress hormone, increase blood sugar
  • Androgens (testosterone)
252
Q

What does the pancreas make?

A
  • Glucagon (increase blood sugar)
    • breaks down glycogen, stimulates gluconeogenesis
  • Insulin (lower blood sugar)
    • stimulates glucose uptake by cells
253
Q

What do the ovaries and testis make?

A

ovaries: estrogen and a small amount of testosterone
testis: make testosterone

254
Q

Major endocrine glands

A
255
Q

Diabetes

A

No insulin made, or no insulin receptors

Glucose can’t enter cells

High blood sugar

Fatty acid metabolism, production of ketone bodies, ketoacidosis

Sugar in urine

256
Q

Hypothyroidism vs Hyperthyroidism

A

Hypo: not enough TH, low metabolism (lack of Iodine- goiter develops from too much TH precursor)

Hyper: too much TH, high metabolism

257
Q

cAMP pathway

A
  1. Amino acid hormone binds to membrane receptor
  2. G-protein activated
  3. Adenylate cyclase activated
  4. cAMP made
  5. Protein kinase cascade
258
Q

Phospholipid pathway

A
  1. Amino acid hormone binds membrane receptor
  2. G protein activated
  3. Phospholipase C activated
  4. Membrane phospholipid split into DAG and IP3
  5. DAG triggers protein kinase cascade
  6. IP3 releases Ca2+ from the ER
259
Q

Steroid pathway

A
  1. Steroid hormone goes inside cell
  2. Hormone binds receptor inside cell
  3. Hormone-receptor complex turns on certain genes inside the nucleus
260
Q

3 normal control of hormones

A
  • Humoral: glands respond to chemical levels in blood
  • Neural: glands release hormones when stimulated by nerves
  • Hormonal: glands release hormones when stimulated by other hormones (tropic hormones)
261
Q

Sensory and Motor nerves

Somatic and Autonomic

A
  • Sensory = Afferent = carry signal to CNS
  • Motor = Efferent = carry signal toward effector organs
    • Somatic (voluntary) - skeletal muscles
    • Autonomic (involuntary) - visceral organs
      • Sympathetic (fight or flight)
      • Parasympathetic (rest)
262
Q

Positive feedback vs Negative

A

Positive: reinforce initial event

Negative: counteracts initial event

263
Q

Reflex arc

A

Receptor → sensory neuron → integration center → motor neuron → effector

(bypasses the brain)

264
Q

Photoreceptors on retina

A

rods (senses light and dark)- most sensitive

cones (senses color)- less sensitive

265
Q

Visual image processing

A
  • Lens of eye, like a convex lens in physics, forms a real image on the retina
  • Real images are inverted
266
Q

Functions of skin

A
  • Heat homeostasis
  • Water homeostasis
  • Osmoregulation
  • Protect against UV radiation (makes melanin)
  • Make vitamin D
  • bblood reservoir
  • Sense
  • Protection
267
Q

what are nails and hair made of?

A

keratin

268
Q

Skin structure

A
269
Q

Male and female gonads

A
  • Male: Testes
    • Make sperm in seminiferous tubules
    • Makes testosterone
    • external
  • Female: ovaries
    • houses immature egg, matures monthly after puberty
    • Makes estrogen
    • internal
270
Q

Male Genitalia

A

Seminiferous tubules, Epididymis, Vas deferens, Ejaculatory duct, nothing, Urethra, Penis

(sevenup)

271
Q

Female monthly cycle

A
  • Primary oocyte matures into secondary oocyte
  • Endometrium thickens, if no fertilization, menses occurs
272
Q

GnRH

A

Stimulates release of FSH and LH

273
Q

FSH

A

follicle stimulating hormone- stimulates the growth and maturation of follicle

Follicle- houses oocyte and produces estrogen

274
Q

Estrogen

A

Normally inhibits LH (leutinizing hormone) and FSH (follicle stimulating hormone), causes LH surge when it eraches a threshold

275
Q

LH

What does LH surge trigger?

A

Leutinizing hormone

stimulates the outer cells of the follicle

turns it into corpus luteum + maintains it

LH surge triggers:

primary oocyte → secondary oocyte → rupture of follicle

276
Q

Corpus luteum

A

makes estrogen and progesterone

maintains endometrium

277
Q

No Fertilization

Fertilization pathway

A

No fertilization → LH falls → corpus luteum dies → estrogen and progesterone fall → endometrium dies (menses) → cycle begins anew with FSH and LH re-rising

Fertilization occurs → implanted embryo releases hCG → hCG mimics LH to maintain corpus luteum → estrogen and progesterone maintained by corpus luteum → placenta takes over the responsibility of making estrogen and progesterone later on

278
Q

Steps of spermatogenesis

A
  • Spermatogonium (2n)
  • primary spermatocyte (2n)
  • secondary spermatocyte (n)
  • spermatid (n)
  • sperm/spermatozoa (n)
279
Q

Oogenesis

A
  • Oogonia (2n)
  • Primary Oocyte (2n)
    • Meiosis I halts at prophase
    • After puberty, meiosis I completes monthly
  • Secondary Oocyte (n)
    • Ovulation (meiosis II halts at metaphase)
    • Sperm contact (meiosis II completes)
  • Mature ovum (n)
    • sperm + egg nuclei
  • Zygote
  • Blastomeres (16-32 cells)
  • Morula
  • Blastocyte
    • Inner cell mass
    • Trophoblast
280
Q

What does endoderm form?

Mesoderm?

Ectoderm?

A
  • endoderm (innermost layer) guts, lungs, digestive internal organs (liver/pancreas)
  • mesoderm (middle layer) muscles, blood, bones, internal organs
  • ectoderm (outermost layer) skin and nerves (including the brain)
281
Q

Fitness

A

ability to pass your genes on, reproductive success

282
Q

Directional selection

A

Selects for a trait on one extreme (ex. tall trees)

283
Q

Stabilizing selection

A

Selects for a trait that is moderate (ex. birthweight)

284
Q

Disruptive selection

A

Selects for the extremes

285
Q

Evolutionary success

A

Increase in percent representation in the gene pool of the next generation

  • If the frequency of an allele increased, then that’s evolutionary success for that allele
  • If the frequency of alleles of an individual increased in a population, then tha’s evolutionary success for that individual
286
Q

Definition of species

A
  • Be able to interbreed
  • Be able to produce fertile, viable offspring
  • Does this naturally
287
Q

Polymorphism

A

Different forms of alleles/traits

288
Q

Bottleneck?

Genetic drift?

A

Bottleneck: severe reduction in populatino size

Genetic drift: random changes in allele frequencies (increases as population size decreases)

289
Q

Divergent Evolution

Parallel Evolution

Convergent Evolution

Coevolution

A
  • Divergent: same lineage, evolving apart to be more different, produces homologous structures
  • Parallel: same lineage, evolving closer together to be similar, using similar mechanisms
  • Convergent: different lineage, evolving closer together to be similar, using different mechanisms
  • Coevolution: 2 species evolve in response to eachother
290
Q

Ontogeny vs Phylogeny

A
  • Ontogeny = development through the life of an organism
  • Phylogeny = development through evolutionary time of lineages/species
291
Q

Chordate

Group of chordates: ___

A

one phylum of the animal kingdom

  • notochord- backbone of the embryo
  • Pharyngeal pouches, branchial arches, gill slits
  • dorsal nerve chords
  • Vertebrate- group of chordates (subphylum)

MCAT Biological Sciences (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions