Chapter 5: the structure and fucntion of large biological molecules

Question 1

All living things are made up of four classes of large biological molecules:

Answer 1

carbohydrates, lipids, proteins, and nucleic acids

Question 2

Within cells, small organic molecules are joined together to form

Answer 2

larger molecules

Question 3

___ are large molecules composed of thousands of covalently connected atoms

Answer 3

Macromolecules

Question 4

Molecular structure and function are ___

Answer 4

inseparable

Question 5

A ___ is a long molecule consisting of many similar building blocks

Answer 5

polymer

Question 6

A polymer is a long molecule consisting of many similar building blocks ​ These small building-block molecules are called ___

Answer 6

monomers

Question 7

Three of the four classes of life’s organic molecules are polymers:​

Answer 7

Carbohydrates​ Proteins​ Nucleic acids

Question 8

A ___ occurs when two monomers bond together through the loss of a water molecule

Answer 8

dehydration reaction (dehydration synthesis)

Question 9

Polymers are disassembled to monomers by ___, the addition of a water molecule, a reaction that is essentially the reverse of the dehydration reaction

Answer 9

hydrolysis

Question 10

Each cell has thousands of different kinds of macromolecules ​

An immense variety of polymers can be built from a small set of monomers

Question 11

___ include sugars and the polymers of sugars

Answer 11

Carbohydrates

Question 12

The simplest carbohydrates are ___, or single sugars

Answer 12

monosaccharides

Question 13

___ consist of two monosaccharides joined by a dehydration synthesis reaction

Answer 13

Disaccharides

Question 14

Carbohydrate macromolecules are ___, polymers composed of many monosaccharides (sugar building blocks)

Answer 14

polysaccharides

Question 15

Monosaccharides have molecular formulas that are usually multiples of CH2O​

Glucose (C6H12O6) is the most common monosaccharide. Other examples are fructose and galactose.​

Monosaccharides are classified by ​

The number of carbons in the carbon skeleton

Question 16

trioses, pentoses, hexoses

Question 17

Though often drawn as linear skeletons, in aqueous solutions many sugars form rings​

Monosaccharides serve as a major fuel for cells and as raw material for building molecules

Answer 17

Question 18

Two monosaccharides can join to form a disaccharide via dehydration synthesis reaction​

This covalent bond is called a ___

Answer 18

glycosidic linkage​

Question 19

Examples of disaccharides include ___

Answer 19

maltose, sucrose and lactose

Question 20

___ the polymers of sugars (may have a few hundred to a few thousand monosaccharides joined).​

​

These have different functions in the cell: ​

Storage roles​

Structural roles

Answer 20

Polysaccharides,

Question 21

___, a storage polysaccharide of plants, consists entirely of glucose monomers

Answer 21

Starch

Question 22

___ is a storage polysaccharide in animals​

Humans and other vertebrates store glycogen mainly in liver and muscle cells

Answer 22

Glycogen

Question 23

The polysaccharide ___ is a major component of the tough wall of plant cells​

Like starch, cellulose is a polymer of glucose, but the glycosidic linkages differ

Answer 23

cellulose

Question 24

Enzymes that digest starch can’t ___ cellulose

Answer 24

hydrolyze

Question 25

Cellulose in human food passes through the digestive tract as ___

Answer 25

insoluble fiber

Question 26

Some microbes use enzymes to digest cellulose (these are called ___)​

Answer 26

cellulase enzymes

Question 27

___, another structural polysaccharide, is found in the exoskeleton of arthropods(ie beetles, lobsters)

Answer 27

Chitin

Chitin also provides structural support for the cell walls of many fungi​

Chitin is similar to cellulose except it has a nitrogen containing functional group on each glucose monomer.

Question 28

Lipids are the one class of large biological molecules that ___

Answer 28

do not form polymers

Question 29

The unifying feature of lipids is having little or no ___

Answer 29

affinity for water

Question 30

Lipids are ___ becausethey consist mostly of hydrocarbons, which form nonpolar covalent bonds

Answer 30

hydrophobic

Question 31

Fats are constructed from two types of smaller molecules: ___

Answer 31

glycerol and fatty acids

Question 32

___ is a three-carbon alcohol with a hydroxyl group attached to each carbon

Answer 32

Glycerol

Question 33

A ___consists of a carboxyl group attached to a long carbon skeleton

Answer 33

fatty acid

Question 34

Fatty acids vary in length (number of carbons) and in the number and locations of double bonds

Question 35

___ fatty acids have the maximum number of hydrogen atoms possible and no double bonds

Answer 35

Saturated

Question 36

___ fatty acids have one or more double bonds

Answer 36

Unsaturated

Question 37

Fats made from saturated fatty acids are called ___, and are solid at room temperature​

Most animal fats are saturated

Answer 37

saturated fats

Question 38

Fats made from unsaturated fatty acids are called ___ or oils, and are liquid at room temperature​

Plant fats and fish fats are usually unsaturated​

Answer 38

unsaturated fats

Question 39

A diet rich in saturated fats may contribute to cardiovascular disease through plaque deposits ​

___is the process of converting unsaturated fats to saturated fats by adding hydrogen

Answer 39

Hydrogenation

Hydrogenating vegetable oils also creates unsaturated fats with trans double bonds​

These trans fats may contribute more than saturated fats to cardiovascular disease​

Question 40

Humans and other mammals store their fat in ___

Answer 40

adipose cells

Question 41

The major function of fats is ___

Answer 41

energy storage

Adipose tissue also cushions vital organs and insulates the body