Example Exam 3

Question 1

What must be bound to the intracellular side of the G protein–coupled
receptor to initiate a secondary messenger

Answer 1

G protein

Question 2

Which signaling feature does the figure depict? (#2 )

Answer 2

Modularity

Question 3

Which signaling feature does the figure depict? (3 )

Answer 3

Integration

Question 4

Which type of receptor is the Na+K+ ATPase

Answer 4

Gated ion channel

Question 5

For all GPCRs, the G protein is:

Answer 5

heterotrimeric.

Question 6

Which is NOT a second messenger for a G protein–coupled receptor?

Answer 6

protein kinase C

Question 7

Which statement is false about type II restriction endonucleases?

Answer 7

They are large, multisubunit complexes containing both endonuclease
and methylase activities.

Question 8

Kanamycin can be used as a _____ marker. In _____ selection, kanamycin
permits the growth of bacteria containing a recombinant plasmid with an
intact kanamycin resistance gene.

Answer 8

selectable; positive

Question 9

What is an advantage of using bacteria as a host for an expression vector?

Answer 9

Bacteria can be grown in huge amounts in commercial fermenters.

Question 10

Simple-sequence repeats (SSRs) are small sequences that are repeated
many times in short segments of tandem repeats. These sequences are a
part of what region of DNA?

Answer 10

Telomeres

Question 11

Which statement about green fluorescent protein (GFP) is false?

Answer 11

GFP requires molecular oxygen and additional proteins and cofactors to
fluoresce.

Question 12

Suppose a mutation is created in a gene, the sequence of the expression
system is verified, and the resulting protein is expressed in yeast. Determine
the MOST likely reason that the function of the protein would not change
upon purification and characterization.

Answer 12

The mutation is silent and does not affect the function of the protein

Question 13

What is the purpose of the secondary antibody in immunofluorescence
methods?

Answer 13

It binds to the primary antibody that is bound to the protein being
detected and produces a fluorescent signal.

Question 14

What is the defining feature of lipids?

Answer 14

Lipids are insoluble in water

Question 15

Lipids that contain simple sugars or complex oligosaccharides at the polar
ends are called:

Answer 15

glycolipids.

Question 16

Consider the fatty acid described by the abbreviation 18:2. How many
double bonds does this compound have?

Answer 16

2

Question 17

For fatty acids, the longer the hydrocarbon chain, the _____ the melting point
and the _____ the water solubility

Answer 17

-higher, lower

Question 18

Which would BEST split a phosphocholine from phosphatidylcholine?

Answer 18

phospholipase C

Question 19

Which structure is NOT an omega-3 (ω-3) polyunsaturated fatty acid
(PUFA)?

Answer 19

20:4 (Δ5,8,11,13)

Question 20

FRAP is a technique that is used to measure:

Answer 20

lateral diffusion in a membrane.

Question 21

Which statement is true about simple diffusion of ions across a
membrane?

Answer 21

Removal of the hydration shell is endergonic, whereas rehydration of
the ion is exergonic

Question 22

Which does NOT apply to the fatty acid structure shown? 21

Answer 22

Delta fatty acid

Question 23

This molecule resembles a triacylglycerol, but it is not. Why can this
molecule NOT be classified as a triacylglycerol?
22

Answer 23

The chain on carbon 3 is not an ester linkage.

Question 24

Cholesterol is synthesized from a large linear precursor called squalene
through a remarkable cyclization reaction involving epoxidation followed
by rearrangement of electrons to produce the steroid nucleus. Squalene is
assembled using individual isoprene groups. How many isoprene units
are used in the construction of one molecule of cholesterol?
23

Answer 24

6

Question 25

Which statement is false regarding transporters and ion channels?

Answer 25

Transporters allow ions to flow down the electrochemical gradient,
whereas channels can move ions against a concentration gradient.

Question 26

Which amino acid would LEAST likely be found in an α helix that spans
a lipid bilayer?

Answer 26

Arg

Question 27

Which statement is true about the chloride-bicarbonate exchanger of the
erythrocyte membrane?

Answer 27

It allows both the entry and exit of bicarbonate into the erythrocyte.

Question 28

. Which enzymes contribute to the asymmetric distribution of
phospholipids in the plasma membrane?

Answer 28

Flippase and floppase

Question 29

Membrane proteins that speed the passage of solutes across membranes
by providing an aqueous path across the membrane are called:

Answer 29

Ion channels

Question 30

G-Protein Coupled Receptor is _____ integral protein.

Answer 30

Polytopic

Question 31

All of these organelles have double membranes EXCEPT for:

Answer 31

Lysosome

Question 32

Amylose and Starch are

Answer 32

Glucose homopolysaccharides

Question 33

What are the components of a nucleotide?

Answer 33

nitrogenous base, pentose, and phosphate

Question 34

Compare the energy released by hydrolysis of phosphate groups
from a nucleotide. Then choose the correct answer.

Answer 34

Release of the γ phosphate releases more energy than the release of
the α phosphate.

Question 35

What is the name of the phosphate group indicated by the arrow on the atp (4)

Answer 35

Alpha

Question 36

The structure in the figure can BEST be described as a:
5

Answer 36

Deoxyribonucleotide

Question 37

The structure pictured can BEST be described as a: 6

Answer 37

Cruciform

Question 38

What is the function of the pictured molecule? 7

Answer 38

Signaling

Question 39

Which statement is false regarding mRNA?

Answer 39

Mrna are the same length

Question 40

What would be expected for the electrophoresis of DNA at pH 7?

Answer 40

DNA migrates toward the positive electrode because the phosphates carry
negative charges.

Question 41

FR

Describe the steps in creating a cDNA library from mouse tissue.

Answer 41

Library is created by inserting cDNA
fragments into vectors and cloning .

1= isolation of the mouse mRNA
2= synthesis 1st strand of cDNA using reverse transcription
3= second strand of cDNA generation using Dna poly
4 Purify
5 incorporation of cDNA into a vector, insert recombinant vectors
6 screen colonies with pcr

Question 42

FR

Compare and contrast symport and antiport. Which term best describes the transport system
mediated by the SERCA pump? What type of ATPase is the SERCA pump? What does it
transport?

Answer 42

Antiports and symports are cortansport systems that transport 2 solutes across a membrane.
Anti= moves in opposite direction
Symp= move in same direction

SERCA pump is a uniporter for Ca2+ ions. It is a P type ATPase.

Question 43

FR

Describe the basic structure and function of P-type ATPases. What some examples of these
membrane proteins?

Answer 43

Pan - phosphorylation domain, actuator domain, nucleotide binding domain

Cation transporters, phosphorylated by ATP as part of transport cycle.

Examples: sodium potassium pump, proton potassium pump

Question 44

FR

The fatty acids that are present in phospholipids are variable in length and degree of
unsaturation. How does this variability effect membranes? How do sterols effect
membranes? Think in terms of melting points, order and disorder. Do cells use these
physical properties to modify the properties of membranes?

Answer 44

Changes in length and DOU changes order and disorder of lipid bilayer. The more cylidindrical the Michelle the more disordered. Sterols affect membrane by making rafts effecting membrane permeability.
Long chain lo
Kink in chain ld
Short chain lo

Question 45

C

Answer 45

Active transport
Uniport because it only shows uptake of histidine