Chapter 5 study questions

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

-

What is a difference between DNA and RNA?

-

Based on complementary base pairing, you would expect the percentage of ____ to be equal to the percentage of____ (Adenine, cytosine, thymine, guanine)

Adenine....Thymine

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

All are associated with the buildup of misfiled proteins in cells

What is true regarding complementary base pairing in DNA and RNA?

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

Which of the following molecules is a monosaccharide? 1. C22H49O10N5 2. C6H12O6 3. C25H43O8 4. C51H98O6 5. C45H84O8PN

C6H12O6

At a conference, the speaker's grand finale was feeing mealworms in butter to the audience. They were crunchy because their exoskeletons contain the polysaccharide...?

Chitin

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

DNA

The monomers in cellulose are linked by...

Glycosidic linkages

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

Microorganisms in their digestive tracts hydrolyze the cellulose to individual glue units

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

Starch

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

The monosaccharide monomers in cellulose are bonded together differently than in starch

If a droplet phospholipid molecule is out in water, all the molecules point outward, toward the water. Phospholipids are forced into this orientation because phospholipids have____

a charged or polar end and an uncharged or non polar end

What describes the chemical components of a nucleotide?

a nitrogenous base, a phosphate group and a pentose sugar

A glucose molecule is to starch as what is to what?

a nucleotide is to a nucleic acid

In a hydrolysis reaction, ____, and in this process water is_____

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

Manufacturers make vegetable oils soil or semisolid at room temperature by____

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

Protein molecules are polymers of what?

amino acid molecules

Lips different from other large biological molecules in that they...

are not true polymers

What component of a tossed salad will pass through the human digestive tract and be digested the least?

cellulose in the lettuce

Which of of the following is a polymer? 1) triacylglycerol, or fat 2) fructose, a component of sucrose 3) cellulose, a plant cell wall component 4) glucose, an energy-rich molecule 5) testosterone, a steroid hormone

cellulose, a plant cell wall component

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

chaperonins

High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body made 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 like sugars and amino acids into polymers like starch is a ______ bond

covalent

The peptide bond is what

covalent bond joining two amino acids

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

dehydration reaction

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

denaturing breaks the intramolecular bonds, such as hydrogen bonds and van der waals interactions, that hold the protein in its three-dimensional 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 triclygycerols are considered to be less healthful than unsaturated triclygcerols. What is the different between them?

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

Which of the following carbs has the lowest molecular mass? 1. cellulose 2. lactose 3. chitin 4. glucose 5. sucrose

glucose

A polysaccharide that is used for storing energy in human muscle and live cell is .....

glycogen

What term can be correctly used to describe compounds that do not mix with water?

hydrophobic

The fatty acid tails of a phospholipid 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 represents a specific description of a polypeptide? 1) carbohydrates with a hydrogen bond holding them together 2) amino acids linked by hydrolysis 3) organic molecules linked by dehydration reactions 4) organic monomers covalently bonded 5) None of the listed responses is correct.

none are correct. a polypeptide chain of amino are linked by dehydration reaction

What is the major energy storage compound of plant seeds?

oils

The lipids that form the main structural component of all cell membranes are_____

phospholipids

What is a true statement comparing phospholids and triacylglycerols?

phospholipids molecules ave distinctly polar head and a distinctly non polar tail whereas triacylglycerols are predominately nonpolar

Cellulose is a ___ made of many _____

polymer...glucose molecules

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

secondary structure

The polysaccharide that you are most likely to have eaten recently is....

starch

Carbs can function in what way?

structural support and energy storage

The overall three-dimensionsal shape of a single polypeptide is called its what structure?

tertiary structure

In a 1-4 glycosidic linkage....

the number 1 caron in one monosaccharide is bound to the number 4 carbon in another monosaccharide

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

What are pyrimidines found in the nucleic acid DNA?

thymine and cytosine

Which of the following lists ranks these molecules in the correct order by size from smallest to largest? water, sucrose, glucose, protein water, protein, sucrose, glucose glucose, water, sucrose, protein protein, water, glucose, sucrose water, glucose, sucrose, protein

water, glucose, sucrose, protein