Biochem Rutgers Murphy Final

conversion of acetyl-CoA to malonyl-CoA is inhibited by

Glucagon, Epinephrine, Palmitoyl-CoA

The recycling rate of triacylglycerols to fatty acids is inhibited by

insulin

Lipolysis is used to

degrade triacylglycerols

Glycerol from the hydrolysis of triacylglycerols is transported by the blood to the

liver

What is the major mechanistic difference in purine and pyrimidine biosynthesis

purines are synthesized on the ring of ribose

How many FADH2 molecules would be produced in the oxidation of palmitic acid (16:0 carbons)

7

Myelin sheath

surrounds nerve cell axons and facilitates nerve impulse transmission

patients with familial hypercholesterolmia

- have missing or defective LDL recpetors

- are homozygous or heterozygous for a nonfunctional LDL receptor gene

- Have very high levels of serum cholesterol

______ are the principal transporters of cholesteryl esters to tissues

low density lipoprotein

the benzene ring of the aromatic amino acids is formed by

shikimate pathway

the pathway in which lipoproteins are transported from the liver to cells is referred to

endogenous pathway

in simple diffusion a solute

is propelled by random molecular motion

inorganic nitrogen is initially assimilated into which of the following amino acids

glutamine

which of the following is not one of the ketone bodies

b-Methylglutarate

all of the following are purine bases except

thymine

prostaglandins are involved in

ovulation, inflammation, and digestion

the principal means of producing glycerol in the body

glyceroneogenesis

depending on an animal's metabolic needs, fatty acids may be converted to triacylglycerols, energy or -------

used in membrane synthesis

Lipid molecules

fatty acids, steroids, isoprenoids, waxes

neutral fats belong to ------

triacylglycerols

------- is used to transport fatty acids into the mitochondria

carnitine

SAM is a methyl donor in the synthesis of -----

methionine, creatine, phosphatidylcholine

fatty acid synthesis begins with the carboxylation of acetyl CoA to form ------

Malonyl-CoA

Membrane remodeling

requires phospholipases and acyl transferases

------, a product of the oxidation of odd-chain fatty acids, is converted to succinyl-CoA

propionyl-CoA

saturated fatty acids containing up to 16 carbon atoms are assembled in

cytoplasm

which of the following is an alpha-keto acid/alpha-amino acid pair used in transamination

oxaloacetate/aspartate

Function of lipids

energy storage, components of biological membranes, insulation, source of acetyl-CoA

Why do most naturally occurring fatty acids have cis double bonds in them

the double bond results in a bend in the molecule lowering the melting point of the molecule.

The fixation of nitrogen requires

Fe-Mo protein, Fe protein, ferredoxin

In plants fixed nitrogen is assimilated into

Glutamine

The major route for protein degradation is

ubiquitin proteasomal system

Fatty acid long carbon tails are referred to as

Acyl

The double bonds in naturally occurring fatty acids are usually _______ isomers.

Cis

Protein channel requiring transport mechanisms include

Primary active transport and facilitated diffusion

All of the following statements concerning folic acid are true EXCEPT:

Folic acid requires intrinsic factor for its absorption in the intestine

the triacylglycerol cycle is

- a mechanism that regulates the level of fatty acids that are available to the body for energy generation

- a mechanism that hydrolyzes triacylglycerol

- converts fatty acids to triacylglycerols

waxes

are esters formed from long-chain fatty acids and long-chain alcohols

who makes who? estradiol vs. testosterone

the enzyme aromatase converts testosterone to estrogen

the function of dolichols is to

transport sugars in glycoprotein synthesis

how many isoprene units does a diterpene contain

4

glycolipids differ from sphingolipids in that they contain no

phosphate

Intermediates in the nonoxidative phase of the pentose phosphate pathway include all of the following except?

dihydroxyacetone phosphate

which of the following is an oxidizing agent in fermentation

pyruvate

gluconeogenesis occurs primarily in the

liver

in nucleosome structure, the histone ----- aids in stabilizing the wrapping of DNA around the protein octomer

H1

Which of the following does not contribute to the noncovalent interactions that stabilize the helical strands of DNA

phosphodiester bonds

which of the following describes the flow of genetic information as stated in the central dogma of molecular biology

DNA--> RNA --> Protein

Nucleosomes are composed of all of the following except

H5

Which of the following is NOT a second messenger molecule/system?

Steroids

which of the following statements is NOT true of mRNA

prokaryotic mRNAs are capped with 7-methylguanosine

the DNA "backbone" is composed of

a phosphodiester bond between 3' and 5' hydroxyl groups of adjacent deoxyribose residues

which of the following amino acids is capable of forming a N-linked glycoprotein

N

which of the following amino acids is capable of forming an O-linked glycoprotein

T

what creates the difference between the blood-group antigens, A, B, and O

all types are O-linked, but possess different sugars

An important role of glycosylation of proteins in the body is

create a diversity of structural possibilities and facilitate extracellular recognition

glucose-6-phosphate is a substrate in which of the following processes

gluconeogenesis and glycolysis

the bifunctional enzyme, PFK-2 would have which of its domains active in response to insulin

the kinase domain

all of the following are important components of the electron transport chain except

Coenzyme A

Evidence supporting the chemiosmotic theory includes all of the following except

the pH of a weakly buffered suspension of mitochondria rises when O2 added

Rap video

energy production

what effect would inhibition of complex 1 of the electron transport chain have on the regulation of pyruvate dehydrogenase (PDH) complex

the increase in NADH would decrease PDH activity

the allosteric regulation of which of the following enzymes is important in the regulation of glycolysis

hexokinase, PFK-1, pyruvate kinase

which of the following enzymes will catalyze a committed step in glycolysis

phosphofructokinase-1

which of the following would be a signal that would lead to an unphosphorylated form of PFK-2/FBPase-2 enzyme

insulin

w-6 fatty acids

have a double bond six carbon atoms from the methyl end of the chain

which of the following is not likely to be a naturally occuring fatty acid

C14H29COOH

A membrane's fluidity is largely determined by the percentage of

unsaturated fatty acids

the role of very low density lipoproteins is

transporting of lipids from liver to tissues

the transamination of alpha ketoglutarate leads to the production of

glutamate

amino acids whose degradation yields a-ketoglutarate include all of the following except

leucine

which of the following amino acids cannot be used to provide an intermediate of the citric acid cycle

Lysine

all amino acids can be synthesized from intermediates of

the glycolytic pathway, the pentose phosphate pathway and citric acid cycle

Which of the following compounds in NOT a precursor for nucleotide biosynthesis

fumarate

The first step of nitrogen fixation is the

Transfer of e- to ferredoxin from NADPH

_________ ATP molecules are required to convert one mole of nitrogen to two ammonia molecules.

16

Nitrogen fixation requires Mo and _________________ as cofactors

Fe

The glutamate family of amino acids includes all of the following except________________

Lysine

Asparagine is formed from aspartic acid and _______________

Glutamine

All of the following are directly involved in the synthesis of deoxyribonucleic acid except_________

HGPRT

Besides PRPP, how many molecules are involved in forming a pyrimidine nitrogenous base?

2

Which of the following statements about hormones are correct?

1. Hormones can be peptides, steroids, or amino acid derivatives

2. Hormones can stimulate the synthesis of target proteins through the activation of specific genes.

4. Hormones can increase the cellular uptake of metabolites

Under which conditions are the lac structural genes expressed least efficiently?

No cAMP, no lactose

In addition to the insulin receptor being able to signal to mTOR and upregulate things like lipid biosynthesis, ribosome biogenesis and translation, another biosenser in the cell can sense energy levels and nutrient availability. This biosensor's name is...?

AMPK

In the image below which of the following represents nucleotide triphosphate that would be incorporated into mRNA?

The upper diagram

Posttranslational modifications include all except

Removal of introns

The process of translation is extremely accurate (1 mistake in 10,000) due to

codon/anti-codon interactions and amino-acyl tRNA synthetases

Which of the following best describes the role of EF-Tu (elongation factor Tu) in elongation of protein synthesis?

It is involved in the correct binding of amino acyl tRNA to the A site of the ribosome

Which of the following statements about the ubiquitination of proteins are true?

1. Ubiquitin is a relatively small protein that is widely expressed in eukaryotic cells

2. It is covalently attached to target proteins in an ATP-dependent rxn

4. Target selection is determined by ubiquitin-protein ligases

Which of the following letters in the diagram below is pointing to the loop that forms the anticodon on tRNA?

Letter E

A researcher will do which fo the following to elucidate how a known steroid receptor protein sends its signal through the cell ultimately changing transcription of a gene. Pick the best choice

Perform a western blot comparing phosphorylated and unphosphorylated versions of a potential kinase target of the receptor molecule

The classic experiment that demonstrated that radioactivity labeled viral DNA transforms bacterial cells was performed by

Hershey and Chase

Why would siRNA be preferred over a chemical inhibitor that targets the same molecule?

Off targets of chemical inhibition may occur where siRNA is specific to a desired mRNA

A western blot is used to detect level of which of the following?

Proteins

Determine the primary sequence of a protein that would be produced from the following non-coding DNA sequence: 5' - GGCCATTTCCCGTAT - 3'

Ile-Arg-Glu-Met-Ala

If the length of the resulting real-time PCR products are identical use the melt curve data below. If peak A consists of DNA with only G-C base pairs and peak E consists of DNA with all T-A base pairs, which of the remaining peaks has the next greatest amount of A-T verses G-C base pairs?

The peak labeled B has the next highest amount of A-T compared to G-C base pairs

Which of the trimeric subunits will hydrolyze GTP to GDP?

The alpha subunit

The following is a hypothetical experimental result obtained after treatment of a cell type with a toxin (Tox) compared to control (control). A western blot was run and the results of the western blot are shown below. Which of the following experiment(s) is/are necessary to run to definitively show that the increase of protein was due to mRNA stabilization only?

- Run real-time PCR on the mRNA of the gene and show no change in level

- Perform a luciferase assay on the promoter of the gene and show no change in level

A protein destine for insertion into the rough endoplasmic reticulum contains a sequence that instructs it to go there. This sequence is called a

Signal Sequence

Which of the following letters in the diagram below point to a carbon donated by 10-formyl-THF during purine biosynthesis?

Both D and E