Chapter 3 Mastering Biology

What is a characteristic of an organic molecule?

Compounds containing carbon are said to be organic.

Monomers are linked together with...

the removal of a water molecule by dehydration synthesis.

In a hydrolysis reaction, _____. In this process, water is _____.

A polymer breaks up to form monomers ... consumed

Hydrolysis means

to break water

A dehydration reaction is the process in which __________.

Water molecules are formed when polymers are synthesized from monomers

Monomers are connected in a reaction in which two molecules are bonded to each other through the loss of a water molecule; this is called a

dehydration synthesis.

Sugars are mainly used by our bodies _____.

fuel

Simple sugar molecules are a major _______ for cellular work.

fuel

One characteristic shared by sucrose and maltose is _____.

they are disaccharides

a disaccharides consists of

two monosaccaraides

Cellulose is a _____ made of many _____.

polymer ... glucose molecules

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

Microorganisms in their digestive tracts hydrolyze the cellulose to glucose.

In what polysaccharide form do plants store sugar to be available later for energy?

starch

Glycogen is _____.

a polysaccharide found in animals

glucose + glucose �> _____ by _____.

maltose + water ... dehydration synthesis

Which of these is a source of lactose?

milk

Cellulose is

a carbohydrate composed of many monomers.

_____ is the most abundant organic compound on Earth.

cellulose

The complex carbohydrate that you are most likely to have eaten recently is _____.

starch

Starch is a storage polysaccharide of

plants

Many carbohydrates are a source

of energy.

Glucose and fructose are

isomers

molecules that share the same chemical composition but differ in their final structures are called

isomers

maltose

glucose

Which is the correct term for compounds that do not mix with water?

hydrophilic

A fatty acid containing at least two double bonds is called _____.

monounsaturated

Cholesterol belongs to which class of molecules?

lipids

RNA is a

nucleic acid

olive oil is a

monounsaturated fat

a chain of amino acids that have been linked together by dehydration synthesis is called a

polypeptide

a peptide bond binds _____.

amino acids

The building blocks of proteins are called _____.

amino acids

A polypeptide is a long chain of amino acids bonded together by __________.

peptide bonds

the building blocks of nucleic acid molecules are called _____.

nucleotides

People with lactose intolerance produce insufficient amounts of _______.

the enzyme, lactase

Lactase breaks down lactose to ________ that can be digested.

smaller sugars

Why might northern Europeans have evolved lactose tolerance?

to increase options for nutrient intake in an environment with a short growing season

The ability ________ would increase the options for acquiring necessary nutrients.

drink milk from herd animals

Which one of the following components of a tossed salad will pass through the human digestive tract with the least digestion?

cellulose (in the lettuce)

Cellulose contains bonds that cannot be broken by...

human digestive enzymes

What is the main sugar used by cells for energy?

glucose

Cells consume glucose for energy in the process of ...

cell respiration

Plant cell walls consist mainly of _____.

cellulose

The polysaccharide called ______ is a major component of the tough walls that enclose plant cells.

cellulose

Manufacturers make vegetable oils solid or semisolid by _____.

adding hydrogens

The characteristic that all lipids have in common is that __________.

none of them dissolve in water

Lipids are _________, causing their solubility in water to be extremely low.

nonpolar

Your body contains thousands of different types of proteins, each with a specific function. A protein's function is largely determined by its _____.

shape

The primary structure of a protein is like the arrangement of beads on a string. In this analogy, the beads are _____.

amino acids

A protein's alpha helices and beta sheets fold together to create an overall shape at the _____ level of protein structure.

third

What happens to the shape and function of a protein if one of the amino acids is replaced with a different type of amino acid?

altered function based on which acid

Large proteins, like DNA polymerase and hemoglobin, are often composed of several polypeptides that are linked together. The _____ level of protein structure describes how the polypeptides are joined to create a larger complex.

fourth

Many people believe you should consume carbohydrates and proteins in what ratio following a long workout?

4:1

What are the constituent parts of proteins?

amino acids

What is the primary fuel source for muscles?

glycogen

What hormone is believed to help muscles absorb amino acids?

insulin

A specific stretch of DNA that programs the amino acid sequence of a polypeptide is called a _____.

gene

A gene is a discrete unit of...

hereditary information

How does DNA compare to RNA?

DNA and RNA consist of monomers called nucleotides.

Nucleotides are the building blocks for both types of nucleic acids called....

RNA and DNA

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

DNA

The backbone of a nucleic acid consists of alternating ________

sugar and phosphate groups

One difference between RNA and DNA?

In RNA uracil is substituted for thymine