Bio Chapter 5 Practice Test

Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein?

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Which of the following describes a difference between DNA and RNA?

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Which of the following represents a specific description of a polypeptide?

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Which of the following molecules is a monosaccharide?

C6H12O6

A shortage of phosphorous in the soil would make it especially difficult for a plant to manufacture _____.

DNA

What is the process by which monomers are linked together to form polymers?

Dehydration reaction

Generally, animals cannot digest (hydrolyze) the glycosidic linkages between glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?

Microorganisms in their giestive tracts hydrolyze the cellulose to individual glucose units.

Amylase is an enzyme that breaks down starch. Why can't the same enzyme break down cellulose?

The mono in cellulose are bounded together differently than in starch

If a small droplet of tri. molecules is suspended in water, the fat molecules form a "ball of spaghetti" with no particular orientation. But if a droplet of phospholipid molecules is put in water, the molecules point outward, toward the water. Phospholipids are forced in this orientation because they have _____.

a charged or polar end and an uncharged or nonpolar end

The peptide bond is?

a covalent bond joining amino acids together to form a polypeptide

Which of the following lists represents the chemical components of a nucleotide?

a nitrogenous base, a phosphate group, and a pentose sugar

A glucose molecule is to starch as _____.

a nucleotide to a nucleic acid

In a hydrolysis reaction, a ______, and in this process water is _____.

a polymer is broken up into its constitute monomers...consumed

Manufacturers make veggie oils solid or semisolid at room temp by?

adding hydrogen atoms to the fatty acid hydrocarbon chains, thereby converting carbon-carbon double bonds to single bonds

Based on the complementary base pairing, you would expect the percentage of _____ to be equal to the percentage of _____.

adenine...thymine

What do Alzheimer's, Parkinson's, and mad cox disease have in common?

all are associated with the buildup of misfolded proteins in the cells

Which of the following is true regarding complementary base pairing in DNA and RNA molecules?

although base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules

Protein molecules are polymers (chains) of?

amino acid molecules

Lipids differ from other large biological molecules in that they _____.

are not truly polymers(phosphlipids contain phosphorous and may contain nitrogen)

Which of the following components of a tossed salad will pass through the human digestive tract and get digested the least?

cellulose (in the lettuce)

Which of the following is a polymer?

cellulose, a plant cell wall component

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?

chaperonins

....They are crunchy because their exoskeletons contain the poly ____.

chitin

High cholesterol levels are considered a major risk factor for heart disease. If it is so bard for humans, why does the body make cholesterol in the first place?

cholesterol is the precursor for many important molecules such as sex hormones

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a _____ bond.

covalent

When a protein is denatured, why does it lose its functionality?

denaturation breaks the intramolecular bonds, such as hydrogen bonds and van der Waals, that hold the protein in its 3-D shape. Without the proper shape, the protein cannot function.

Carbs are used in our bodies mainly for ____.

energy storage and release

Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by _____.

ester linkages

Nutritionally, saturated tricyglycerols are considered to be less healthful than unsaturated triacylglycerols. What is the difference between them?

for carbon skeletons of equal length, saturated triacylglycerols have more hydrogen atoms than unsaturated

Which of the following carb molecules has the the lowest molecular mass?

glucose

A poly that is use for storing energy in human muscle and liver cells is?

glycogen

The subunits (monos) in cellulose are linked together by ____.

glycosdic linkages

Which of the following terms can be correctly used to describe compounds that do not mix well with water?

hydrophobic

The fatty acid tails of a phos are _____ because they ____.

hydrophobic... have no charges to which water molecules can adhere

The sex hormones estradiol and testosterone belong to which class of molecules?

lipids

What is a distinguishing feature of most naturally occurring unsaturated fats?

nearly all naturally occurring unsaturated fats have cis double bonds

Which of the following is the major energy storage compound of plant seeds?

oil

The lipids that form the main structural component of cell membranes are?

phospholipids

Which of the following is a true statement comparing phospholipids and tris (fats and oils)?

phospholipids molecules have a distinctly polar "head" and a nonpolar "tail", whereas tris are predominantly nonpolar

Cellulose is a ____ made of many _____.

polymer...glucose molecules

The alpha helix and beta pleated sheet represent which level of protein structure?

secondary structure

In what polysaccharide form do plants store glucose to be available later as an energy source?

starch

The ploy that you are most likely to have eaten recently is?

starch

Carbs can function in which of the following ways?

structural support and storage

The overall three-dimensional shape of a single polypeptide is called its?

tertiary structure

In a 1-4 linkage, ____.

the number 1 carbon is one mono bound to the number 4 carbon in another

The "primary structure" of a protein refers to?

the sequence of amino acids along a polypeptide chain

One characteristic shared by sucrose, lactose, and maltose is that?

they are all disaccharides

Which of the following are pyrimidines found in the nucleic acid of DNA?

thymine and cytosine

Which of the following lists ranks these molecules in the correct order by size from smallest to largest?

water, glucose, sucrose, protein