Kaplan FL 1 Flashcards BIOCHEM 2

Question 1

what do competitive inhibitors do?

Answer 1

they INCREASE Km
Vmax satys the same

Question 2

How does competitive inhibitor look on Lineweaver Burke plot?

Answer 2

Lineweaver Burk

x intercept closer to 0 (bigger Km)
same y intercept (same Vmax)

Question 3

How does competitive inhibitor look on Michealis Menton plot?

Answer 3

V max is the same
Km increases which means more substrate is needed to reach Vmax

Km is 1/2 Vmax

Question 4

What does Lineweaver Burke plot look like

Answer 4

Question 5

What does the Michealis Menten plot look like?

Answer 5

Question 6

cooperative enzymes

Answer 6

Certain enzymes do not show the normal hyperbola when graphed on a Michaelis–Menten plot (v vs. [S]), but rather show sigmoidal (S-shaped) kinetics owing to cooperativity among substrate binding sites

Subunits and enzymes may exist in one of two states: a low-affinity tense state (T) or a high-affinity relaxed state (R). Binding of the substrate encourages the transition of other subunits from the T state to the R state, which increases the likelihood of substrate binding by these other subunits. Conversely, loss of substrate can encourage the transition from the R state to the T state, and promote dissociation of substrate from the remaining subunits.,

Question 7

example of cooperative binding enzyme in glycolysis

Answer 7

Enzymes showing cooperative kinetics are often regulatory enzymes in pathways, like phosphofructokinase-1 in glycolysis. Cooperative enzymes are also subject to activation and inhibition, both competitively and through allosteric sites.

The cooperative binding of hemoglobin, which acts as a transport protein rather than an enzyme, results in a characteristic sigmoidal binding curve that is an MCAT favorite.

Question 8

What is Hills coefficient?

Answer 8

number for the cooperativity of an enzyme

if >1, positive cooperative binding such that after one ligand is bound the affinity of the enzyme for further ligand(s) increases.

If < 1, negatively cooperative binding is occurring, such that after one ligand is bound the affinity of the enzyme for further ligand(s) decreases.

If = 1, the enzyme does not exhibit cooperative binding.

Question 9

Find the equilibrium constant expression

Answer 9

pure solids and pure liquids are NOT part of equilibrium expression– only nitric oxide and water vapor

Question 10

alpha galactose and beta galactose

Answer 10

beta is up and alpha is down

Question 11

what anomer of galactosidases does Beta galactosidase work on?

Answer 11

it catalyzes hydrolysis of terminal beta D galactose residues into Beta D galactosides

Question 12

what does beta fructopyranose look like?

Answer 12

Question 13

what are the ways to alter gene product to make long and short versions of a gene

Answer 13

1. transcriptional processing via alternative splicing to make 2 diff mRNA for 2 diff products

specific sequences are selected to remove

2. after translation the longer version is cleaved to make the shorter one

Question 14

a way to measure proton leak besides H+ flow across inner mitochondrial membrane

Answer 14

oxygen consumption

its the final electron acceptor in ETC and as protons leak through UCPs oxygen will be consumed as the ETC pumps more protons into the intermembrane space

more oxygen consumed as more protons leak

Question 15

if a child inherits 1 maternal copy of a PAH gene and 1 paternal copy of BH4 gene what is the probability of having PAH disease

assume PAH and BH4 have autosomal recessive inheritance

Answer 15

bc the child has 1 but not 2 genes of each disease they will not have
PKU or BH4 disease

chance = 0

Question 16

what is FISH

Answer 16

flourescence in situ hybridization - uses flourescent probes to bind to parts of a nucleic acid sequence. Used to find a specific feature in a dna sequence not a protein

Question 17

southern blot

Answer 17

identifies differences in DNA sequences using gel electrophoresis

Question 18

northern blotting

Answer 18

detects RNA sequences using electrophoresis

Question 19

western blot

Answer 19

seperation and identification of proteins using size in electrophoresis

Question 20

karyotyping

Answer 20

views metaphase chromosomes not proteins

Question 21

do RBC have mitochondria? how do they make ATP?

Answer 21

no membrane bound organelles
no mitochondria

produce E anerobically via glycolysis and are unaffected by drugs that disrupt ETC

Question 22

what kind of DNA do mitochondria have and is it enclosed in a membrane?

Answer 22

they have circular DNA that is surrounded by a nuclear membrane

Question 23

what happens to heart rate, inhalation, tidal volume and, erythropoietin in high altitudes

Answer 23

less O2 at higher altitude
body wants to increase O2 intake or delivery

• heart rate INC to deliver O2 to tissues
• inhalation increases to get in O2
• tidal volume (amt air breathed in a breath) increases to increase O2
• eryhropoietin by the kidneys stimulates increased RBC production to increase oxygen carrying capacity

Question 24

what is the structure of an antibody? What and where is the variable region?

Answer 24

variable region binds the antigen and has heavy and light chains

Question 25

mutation causing least damadge ( and is prevelant)

Answer 25

point mutation

only 1 base is affected
usually not lethal bc of redundancy in genetic code for proteins

Question 26

oligomycin is a ATP synthase inhibitor (final stage of OxPhos)

if ATP levels in some myoblasts was LESS sensitive to oligomycin than it might indicate that….

Answer 26

they rely more on glycolysis than WT myoblasts do

Question 27

if a female mouse with a mutation in reducec ATP in mitochondrial DNA is mated with male mouse with no mutation what is the chance offspring have the mutation

Answer 27

100 percent
mitochondrial mutations have maternal influence and will be passed

Question 28

what is negative selection of T cells and where does it occur ?

Answer 28

negative selection involves apoptosis
Mediated through mitochondria using release of cytochrome c

Question 29

Where can apoptosis be initiated?

Answer 29

In the mitochondria by release of cytochrome c

Question 30

What does the mesoderm develop into

Answer 30

Muscle, circulatory system, kidney, bone marrow

Question 31

Liver and Lung cells are derived from what Germ layer

Answer 31

Endoderm

Question 32

Nerve cells are from what layer

Answer 32

Ectoderm

Question 33

Bone marrow produces what types of cells

Answer 33

All leukocytes in the immune system including T cells

Bone marrow and kidneys are made from same germ layer, mesoderm

Question 34

Succinate cytochrome c reductase is involved in what biochemical process

Answer 34

Krebs and ETC

Question 35

SDS Page Separates components by

Answer 35

Molecular weight

Question 36

Phosphotases vs kinases

Answer 36

Phosphotases remove phosphate
Kinases add phosphates

Question 37

back mutation

Answer 37

second mutation restors original function of gene which results in a NORMAL gene product

Question 38

nonsense vs missense vs sense mutation

Answer 38

nonsense - mutation codes for STOP codon

missense - mutation changes codon for one amino acid into codon for another one

sense - DNA sequence still codes for same amino acid

Question 39

how can a frameshift mutation cause a protein product lacking 50 amino acids near the C terminus?

Answer 39

frameshift addition or deletion can disrupt codon set causing misalignment of amino acids to code for stop codon and delete last 50 amino acids

Question 40

somatic mutations early in development often occur in the

Answer 40

S phase
DNA replication phase

Question 41

phases of cell divivision

Answer 41

G1 - cell increases organelles and cytoplasm

G2 - growth again

M - division into 2 cells

Mitosis - PMAT
Meisos - PMAT * 2