Biochem Flashcards by Carl Soriano

Chiral Carbon

Carbon with four different groups attached

How well did you know this?

Not at all

Perfectly

D-Configuration

Dextro: Latin for on the right side
the functional group is pointing on the right side of the highest numbered chiral carbon

How well did you know this?

Not at all

Perfectly

L-Configuration

Levo: Latin for on the left side
the functional group is pointing on the leftside of the highest numbered chiral carbon

How well did you know this?

Not at all

Perfectly

simplest carbohydrate

glyceraldehyde

How well did you know this?

Not at all

Perfectly

Glucose and fructose are examples of

single sugars

How well did you know this?

Not at all

Perfectly

(CH2O)n is the molecular formula for
which type of macromolecules?

Carbohydrates

How well did you know this?

Not at all

Perfectly

Which of the following is NOT a
polysaccharide?

A. Glycogen
B. Starch
C. Sucrose
D. Cellulose

Sucrose

How well did you know this?

Not at all

Perfectly

What are used in animals as a source of
quick energy that can be stored in the
liver and muscles ?

Carbohydrates

How well did you know this?

Not at all

Perfectly

Sugars, starches, and cellulose belong
to which major class of biological
molecules?

carbohydrates

How well did you know this?

Not at all

Perfectly

Plants like sugar cane and sugar beets store
the energy as simple sugars. Other plants,
like corn and potatoes, store the energy as
more complex sugars called?

starches

How well did you know this?

Not at all

Perfectly

Which macromolecule does not
dissolve in water?

lipids

How well did you know this?

Not at all

Perfectly

natural fatty acids

C10 to C20 natural fatty acids capric, lauric,
myristic, palmitic, stearic and arachidic is:
“Carla, Laura & Maria Perform Silly
Antics”

How well did you know this?

Not at all

Perfectly

What are the monomers of lipids?

Fatty acids and glycerol

How well did you know this?

Not at all

Perfectly

Lipids are used by the body to perform all
of the following functions EXCEPT:

A. membrane structural material.
B. enzyme action.
C. insulation.
D. a rich energy source.

enzyme action.

How well did you know this?

Not at all

Perfectly

What type of organic substances are
fats?

lipids

How well did you know this?

Not at all

Perfectly

Fats that have fatty acids with only single
covalent bonds in their carbon skeletons
are

saturated

How well did you know this?

Not at all

Perfectly

Which of the following is a polymer?

A. nucleic acid
B. fatty acid
C. Amino acid
D. Glycerol

nucleic acid

How well did you know this?

Not at all

Perfectly

This biological macromolecule is
responsible for controlling the activity of the
cell, and it stores and transports genetic
information.

Nucleic acid

How well did you know this?

Not at all

Perfectly

What are described as the “building
blocks of Protein”?

Amino Acids

How well did you know this?

Not at all

Perfectly

Proteins are ___ made of amino
acid __

polymers; monomers

How well did you know this?

Not at all

Perfectly

In this type of structure, most of carbonyl
groups of peptide bonds forms a hydrogen
bond with the amide nitrogen of another
peptide bond four amino acids further down
the polypeptide chain:

Alpha-helix

How well did you know this?

Not at all

Perfectly

The isoelectric point of an amino acid is defined
as the pH

where the molecule carries no electric charge

How well did you know this?

Not at all

Perfectly

When the amino acid alanine (R-
group is CH3) is added to a solution

with a pH of 7.3, alanine becomes

an anion

How well did you know this?

Not at all

Perfectly

The term “SALTING IN” refers to?

B.Increasing the solubility of a protein in
solution by adding ions.

How well did you know this?

Not at all

Perfectly

The local spatial arrangement of a polypeptide’s backbone atoms without regard to the conformation of its side chains can be called as

Secondary structure

Which of the following amino acids are more likely to be found in a protein’s interior away from aqueous solvent molecules?

Val, Leu, Ile, Met, and Phe

Which of the following is (are) true of - turns in proteins? A. It is a 180o turn of four amino acids. B.Glycine and proline are frequently found there. C.Are used as connecting turns of - helix D. All of the above.

D. All of the above.

The primary stabilizing force of protein secondary structure is:

Hydrogen bonds

Two types of -pleated sheets can be called:

parallel and antiparallel

Which of the following is NOT a characteristic of a globular protein? * A Polypeptide chain in extended, long sheets * B Polypeptide chains are folded in a spherical shape. * C Contains several types of secondary structure * D Typical for regulatory proteins.

A Polypeptide chain in extended, long sheets

The alpha helix found in myoglobin can best be described as

Secondary structure

Some parts of a protein that have a specific chemical structure and function are called protein

domains

One of the following is NOT usually a force that helps to hold the monomer units of a quaternary protein together? A. Peptide bonds B. Disulfide bonds C. Salt bonds D. Hydrophobic interactions

Peptide bonds

One of the following is NOT usually a force that helps to hold the monomer units of a quaternary protein together? A. Peptide bonds B. Disulfide bonds C. Salt bonds D. Hydrophobic interactions

Peptide bonds

If a person breathes into a paper bag, you would expect their blood CO2 to

D. increase and their blood pH to decrease

The quaternary structure of a protein is

the intertwining of two or more polypeptides

The action of disrupting the three- dimensional shape of a protein is termed

denaturation

Glycolytic pathway regulation involves * A. allosteric stimulation by ADP * B. allosteric inhibition by ATP * C. feedback, or product, inhibition by ATP * D. all of the above

D. all of the above

Why does the glycolytic pathway continue in the direction of glucose catabolism?

There are essentially three irreversible reactions that act as the driving force for the pathway

The released energy obtained by oxidation of glucose is stored as

ATP

For every one molecule of sugar glucose which is oxidized _ molecule of pyruvic acid are produced.

The enzymes of glycolysis in a eukaryotic cell are located in the

C.cytosol

Which of the following is not true of glycolysis? * A.ADP is phosphorylated to ATP via substrate level phosphorylation * B.The pathway does not require oxygen * C.The pathway oxidizes two moles of NADH to NAD+ for each mole of glucose that enters * D.The pathway requires two moles of ATP to get started catabolizing each mole of glucose

C.The pathway oxidizes two moles of NADH to NAD+ for each mole of glucose that enters

ATP is from which general category of molecules?

A.Polysaccharides

Which of the following regulates glycolysis steps? A.Phosphofructokinase * B.Hexose kinase * C.Pyruvate kinase

D.All of these

Which of the following is not a mechanism for altering the flux of metabolites through the rate-determining step of a pathway? * A. Allosteric control of the enzyme activity * B. Block active sites * C. Genetic control of the enzyme concentration * D. Covalent modification of the enzyme

Block active sites

Phosphofructokinase, the major flux-controlling enzyme of glycolysis is allosterically inhibited and activated respectively by A.ATP and PEP * B.AMP and Pi * C.ATP and ADP * D.Citrate and ATP

C.ATP and ADP

Where does glycolysis occur? A. inner membrane of mitochondria B. matrix of mitochondria C. stroma of chloroplast D. cytoplasm

cytoplasm

Sports physiologists wanted to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for a buildup of which of the following compounds? A. oxygen B. ATP C. lactate D. carbon dioxide

lactate

There are four enzymes of gluconeogenesis that circumvent the irreversible steps in glycolysis. When starting with the substrate pyruvate or lactate they are A.Hexokinase, phosphofructokinase-1, phosphofructokinase-2 and pyruvate kinase B.Pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1,6-bisphosphatase, and glucose-6-phosphatase C.Glycerol kinase, glycerol-3-phosphate dehydrogenase, fructose-2,6-bisphosphatase, and glucose-6-phosphatase D.Amino transferase, phosphoenolpyruvate carboxykinase, fructose-2,6-bisphosphatase, and glucose-6-phosphatase

B.Pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1,6-bisphosphatase, and glucose-6-phosphatase

The enzymes that remove phosphate groups during the process of gluconeogenesis and circumvent two of the three irreversible reactions of glycolysis are * * A. Pyruvate kinase and glycerol kinase B.Phosphoenolpyruvate carboxykinase and glycerol kinase C.3-Phosphoglycerate kinase and fructose-1,6- bisphosphatase D.Fructose-1,6-bisphosphatase and glucose-6- phosphatase

D.Fructose-1,6-bisphosphatase and glucose-6- phosphatase

The most important control step in gluconeogenesis is fructose-1,6- bisphosphatase. All of the following statements are true EXCEPT * A.Fructose-1,6-bisphosphatase converts fructose-2,6-bisphosphate to fructose-6-phosphate B.During times when insulin is high, fructose-1,6-bisphosphatase is inhibited by fructose-2,6-bisphosphate C.During a fast or exercise when glucagon and/or epinephrine are high, fructose-1,6-bisphosphatase is active because of the absence of fructose-2,6-bisphosphate D.Glycolysis or gluconeogenesis cannot be active at the same time. If they were is would be a futile cycle

A.Fructose-1,6-bisphosphatase converts fructose-2,6-bisphosphate to fructose-6-phosphate

In the liver, glucagon will activate A. Glycolysis and glycogen synthesis B. Gluconeogenesis and glycogenolysis C. Gluconeogenesis and glycogen synthase D. Gluconeogenesis and glycogen synthesis

B. Gluconeogenesis and glycogenolysis

Which of the following statements about hormonal levels during different states is true? A.During the time you are eating a high carbohydrate mixed meal, the insulin to glucagon ratio will decrease B.When passing from the fed to fasting state, insulin and glucagon usually decrease C. When playing basketball, epinephrine is usually low and insulin is high D.After running for 20 miles, epinephrine and glucagon are high and insulin is low

D.After running for 20 miles, epinephrine and glucagon are high and insulin is low

All of the following will result in activation of glycogen phosphorylase in skeletal muscle EXCEPT A.Increased concentrations of AMP from contraction of muscle B. Increased epinephrine and cAMP C. Increased cytosolic [Ca++] D. Increased protein phosphatase E. Increased activity of glycogen phosphorylase kinase

D. Increased protein phosphatase

Catabolism:

Breaking down of molecules

Anabolism:

Building up of molecules

glycolysis ratio

glucose:pyruvate:atp:acetylcoa = 1:2:2:2 molecules

Energy investment phase

— uses two ATP — irreversible steps: glucose to glucose-6-phosphate (hexokinase) and fructose-6-phosphate to fructose-1,6-biphosphate (phosphofructokinase)

Energy Yielding phase

— irreversible phase: phosphoenolpyruvate to pyruvate (pyruvate kinase) — 4 ATP are produced

Glycolysis Summary:

* Energy investment phase — uses two ATP — irreversible steps: glucose to glucose-6-phosphate (hexokinase) and fructose-6-phosphate to fructose-1,6-biphosphate (phosphofructokinase) * Energy Yielding phase — irreversible phase: phosphoenolpyruvate to pyruvate (pyruvate kinase) — 4 ATP are produced Intotal, two ATPs are produced (+4-2)

gluconeogenesis

pyruvate to glucose