CHE 110 Practice Exam 4 Questions

Flashcards created to help review key concepts and facts for CHE 110 exam preparation.

Water soluble amines are and tend to the pH of solutions.

weak bases/raise

Some drugs that contain amino groups are converted to their salts to increase their _.

solubility

Novocain, a local anesthetic, is used rather than procaine because _.

amine salts are soluble in body fluids.

Nitrogen-containing compounds that are physiologically active and are produced by plants are known as _.

alkaloids

Guanine (DNA base) has _ functional group(s).

amine and amide

Caffeine, nicotine, and cocaine are all classified as _.

alkaloids

Almost all proteins are composed from a set of how many different amino acids?

twenty

Valine, shown here, is an amino acid that is classified as _ due to its 'R' group. This creates _ interactions within a protein.

non-polar, hydrophobic

Chemically, proteins are _.

polyamides

The type of bond that links amino acids together is a _.

peptide bond

To indicate the order of a segment of peptide as Lys-Gly-Ala-Cys is to describe its _ structure.

primary

By describing the relative position of the four polypeptide chains of hemoglobin, we specify the structure of hemoglobin as _.

quaternary

The a-helix describes what kind of protein structure?

secondary

The structure of collagen can be described as a(n) _.

triple helix

When a protein is denatured, the structure reverts to .

the primary structure of the protein

All of the following could cause a protein to denature except _.

lowering the temperature

When a protein undergoes hydrolysis, the structure reverts to .

the individual amino acids that make up the protein

A compound that catalyzes a chemical reaction in a living organism is called a(n) _.

enzyme

Enzymes belong to which class of organic compounds?

proteins

The compound that has a reaction catalyzed by an enzyme is called a(n) _.

substrate

Which theory of enzyme action states that the active site can be flexible and adapt to the shape of the substrate?

Induced-fit model

The optimum temperature for most enzymes operating in the human body is _.

37 °C

Trypsin, a peptidase that hydrolyzes polypeptides, functions in the small intestine at an optimum pH of 8. All except which of the following would decrease the rate of a trypsin-catalyzed reaction?

Adding more trypsin

Which of the following is a type of enzyme that is produced as an inactive form and stored for later use?

Zymogen

All except which of the following describe a competitive enzyme inhibitor?

The effect of the inhibitor cannot be reversed by adding more substrate.

Which of the following enzymes does not require a cofactor?

One whose active form consists of two polypeptide chains.

Vitamins are _.

organic molecules that an organism requires in trace amounts but cannot synthesize for itself.

Which of the following is a water soluble vitamin?

Vitamin C

What type of enzyme regulation changes the shape of the enzyme to allow the substrate to bind more effectively?

Positive allosteric regulator

The fat-soluble vitamin whose deficiency causes a condition called rickets (softening of the bone) due to lack of calcium absorption is _.

vitamin D, or cholecalciferol

A patient shows up at an emergency room with methanol poisoning. The enzyme alcohol dehydrogenase converts methanol to toxic formaldehyde. The ER physician orders the patient to be dosed with ethanol, a different alcohol with less toxic products. This is an example of _.

competitive inhibition

What does the T in ATP stand for?

tri

Which of the following nitrogen bases is not a pyrimidine?

adenine

Nucleosides and nucleotides differ in that only a nucleotide contains _.

a phosphate group

A nucleotide in DNA contains which of the following?

phosphate

DNA strands from the double helix are held together with bonds.

hydrogen

DNA is never replicated. All strands in the body are different.

false.

Which of the following is a complementary base pair in DNA?

A-T.

Which of the following bases is found in RNA and not in DNA?

uracil.

Which of the following is not a type of RNA?

L-shaped RNA.

Which base is not normally found in RNA?

thymine.

What is the mRNA sequence produced from a section of the template strand of DNA that has this sequence of bases: 3’ C A A T G C C T 5’

5’ G U U A C G G A 3’.

During protein synthesis, it takes _ mRNA bases to produce one amino acid.

3.

PCR stands for

Polymerase chain reaction.

A vaccine contains small quantities of live virus.

false.

Cancer can be caused by

all of the above.

When active protein synthesis is taking place in the cell, which material is not required at the ribosomes?

DNA.

Which type of genetic mutation has one base replaced with a different base?

Point mutation.

What is the difference between catabolic and anabolic reactions?

Catabolic reactions break down molecules, while anabolic reactions build new molecules.

Which process releases the most energy?

Converting ATP to ADP.

Digestion of carbohydrates begins with

amylase in the mouth.

Which of the following are the reactant and product of glycolysis?

Glucose is the reactant; pyruvate is the product.

Glucose is a necessary part of our metabolism and can only be obtained in the body by eating carbohydrates.

False, glucose can be synthesized in the body from non-carbohydrate sources.

What is the name of the process when glucose is produced from non-carbohydrate sources once glucose and glycogen stores have been used?

gluconeogenesis.

Excess glucose that does not produce pyruvate and ATP is used to synthesize

glycogen.

Adrenaline is released in “fight or flight” situations. What is the scientific name for this hormone and what does it do?

Epinephrine, raises blood sugar.

Under aerobic conditions in the human body, the pyruvate formed from glycolysis is converted to _.

acetyl-CoA and CO2.

Under anaerobic conditions in the human body, the pyruvate formed from glycolysis is converted to _ which can cause sore muscles.

lactate.

In fermentation, pyruvate is converted to _.

ethanol.

Glycogen is a type of

polysaccharide.

Which hormone triggers a decrease in blood sugar levels?

insulin.

Which is NOT true about the citric acid cycle?

It produces lactate in the muscles.

What is the molecular formula of glucose?

C6H12O6.

Which is not a method of producing ATP?

lipid synthesis.

What happens to most of the energy that is not stored in the body?

It is given off as heat.

Storing ATP is approx. _ efficient in the body.

33%.

The energy yield in ATP molecules from the complete oxidation of glucose is _.

32 ATP.

ATP is the only form of stored energy in the body.

False.

Amino acids in the body can be used to synthesize

both new proteins and nitrogen containing compounds such as DNA/RNA, neurotransmitters, and hormones.

The complete digestion of triacylglycerols produce

A and B.

ATP can be produced from oxidation of fatty acids.

true.

How many ATP are produced during the b-oxidation of an 18-carbon fatty acid?

120.

In diabetes, insulin does not function properly, so blood glucose is typically and glucose in the cells is typically .

high/low.

If the body has met all its energy needs and glycogen stores are full, extra carbohydrates are used to synthesize

extra fatty acids to store in fat cells.

Anabolic pathways produce molecules and __ energy.

large / requires.

High concentrations of ketones in the blood _.

are a symptom of starvation.

All of the following are true about the synthesis of fatty acids except that _.

they are excreted in the urine.

Proteins are not broken down in the body. They are only used to build muscle.

False, they are broken down and used to reform new proteins among other uses.

Excess nitrogen from amino acids is excreted in

urine.

Which is the least likely to be used to degrade into Acetyl-Co A for use in the citric acid cycle?

carbohydrates.

A glucogenic amino acid is one that can be used

to make glucose.

All of the following compounds need amino acids for their synthesis because they contain nitrogen except _.

carbohydrates.

Non-essential amino acids are ones that

our body can produce.

The biosynthesis of muscle protein from amino acids is classified as _.

anabolism.

The source of nitrogen in urea is _.

proteins.

Which of the following can ultimately lead to the production of ATP?

Carbs, fats, and proteins.