Honors Biology Ch 3

The Molecules of Cells module

Fatty acids, unsaturated fats, saturated fats, and cholesterol are alike in which of the following ways?

They do not mix well with water.

Cellulose is a _________ made of many __________ linked together with _________ bonds.

polymer; glucose molecules; covalent

Which component of the core structure of an amino acid makes the molecule acidic?

carboxyl group

Which functional group can transfer energy among organic molecules?

phosphate

Why are the two strands of DNA called "complementary"?

The base sequence of one strand exactly predicts the base sequence of the other.

Here is the chemical formula for glucose: C6H12O6. Maltose is a disaccharide formed when two glucose molecules combine via a dehydration reaction. Using this information, determine the chemical formula of maltose.

C12H22O11

The average American consumes approximately __________ times the amount of sugar recommended by the World Health Organization.

six

Which of the following statements is correct regarding double-layered cell membranes?

The phosphate-glycerol heads face the watery environment.

Which of the following is the best description of “R” groups of an amino acid?

carbon atoms with different functional groups attached

When comparing DNA and RNA, only one of these choices is correct. Which one?

DNA directs the synthesis of RNA, which is used to synthesize protein.

When you eat a piece of cheese, which of the following occurs for you to break down the polymers in the cheese and then rebuild them into polymers you need in your cells?

hydrolysis, then dehydration

Which of the following statements about carbon skeletons is correct?

Carbon skeletons can be straight or in the shape of a ring.

The backbone of protein molecules coils or folds into local patterns. This gives the protein its __________ structure. A protein composed of more than one polypeptide chain has a __________ structure.

secondary; quaternary

In hydrolysis, which of the following occurs?

A polymer is broken down by the addition of water; water is consumed.

Which protein type speeds up chemical reactions?

enzymes

Which protein type provides nutrients?

storage proteins

Which protein type moves materials?

transport proteins

Sucrose, the most common disaccharide, is made of a __________ molecule joined to a __________ molecule by means of a __________ reaction.

glucose, fructose, dehydration

What could alter or destroy the function of a protein?

a genetic mutation that changes the amino acid sequence; excessive heat; moving a protein that functions in a neutral environment to an acidic solution; placing a protein that functions in an acidic environment into a neutral solution

The "building blocs" of the nucleic acids DNA and RNA are called __________. These building blocks are __________.

nucleotides; monomers

What is the correct sequence of events in gene expression?

DNA to RNA to protein

Lactose intolerance appears to be the "norm" for humans, yet many Northern Europeans happily consume large quantities of milk and cheese. Which of the following probably led to the high prevalence of lactase in Northern Europeans?

The cold climate of Northern Europe likely forced people to rely on dairy products.

Which of the following side effects is not linked to anabolic steroid use?

improvement in mood

According to the long-term Nurse's Health Study, which of the following foods is associated with the lowest relative risk of heart disease?

polyunsaturated fats

In chemistry, an "organic" compound is a compound with which of the following characteristics?

It always contains carbon atoms.

Your apartment has a cockroach problem. When you walk across your kitchen floor late at night, you hear “CRUNCH, CRUNCH” as you trample on an army of cockroaches. What substance in the insects’ bodies produces that sound, and to what category of polysaccharide does it belong?

chitin; structural polysaccharide