Chapter 03

Front 1

What do functional groups do?

Back 1

They give specific properties to molecules

Front 2

How are functional groups bonded?

Back 2

They are covalently bonded to organic molecules

Front 3

What comprises an amino acid?

Back 3

A carboxyl group and an amino group

Front 4

Look at figure 3.1

Back 4

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Front 5

What are four major types of biological macromolecules?

Back 5

Proteins
Carbohydrates
Lipids
Nucleic acids

Front 6

What are macromolecules?

Back 6

Giant polymers

Front 7

How are polymers formed?

Back 7

By covalent linkages of smaller units called monomers

Front 8

Look at figure 3.4

Back 8

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Front 9

What are proteins?

Back 9

They are polymers of amino acids. They are molecules with diverse structures and functions

Front 10

An amino acid has four groups attached to a central carbon atom. What are these four groups?

Back 10

A hydrogen atom
An amino group (NH3+)
The acid is a carboxyl group (COO–).
Differences in amino acids come from the side chains, or the R groups.

Front 11

Look at figure 3.5

Back 11

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Front 12

How are proteins synthesized?

Back 12

By condensation reactions between the amino group of one amino acid and the carboxyl group of another. This forms a peptide linkage which forms a polypeptide

Front 13

Look at figure 3.6

Back 13

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Front 14

What are the four levels of protein structure?

Back 14

Primary, secondary, tertiary, and quaternary

Front 15

The precise sequence of amino acids is called what?

Back 15

Its primary structure

Front 16

The peptide backbone consists of repeating units of what atoms?

Back 16

N—C—C—N—C—C

Front 17

Look at figure 3.7

Back 17

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Front 18

What does a proteins secondary structure consist of?

Back 18

Regular, repeated patterns in different regions in the polypeptide chain. This shape is influenced primarily by hydrogen bonds arising from the amino acid sequence (the primary structure).

Front 19

What are the two common secondary structures in a protein?

Back 19

The a helix and the b pleated sheet

Front 20

Describe the a helix

Back 20

The a helix is a right-handed coil.
The R groups point away from the peptide backbone

Front 21

How do β pleated sheets form ?

Back 21

β pleated sheets form from peptide regions that lie parallel to each other. Stabilized by hydrogen bonds between N-H groups on one chain with the C=O group on the other.

Front 22

What is the tertiary structure ?

Back 22

It is the three-dimensional shape of the completed polypeptide where there are interaction between R groups

Front 23

What are the factors that determine tertiary structure?

Back 23

The nature and location of secondary structures
Hydrophobic side-chain aggregation and van der Waals forces, which help stabilize them
The ionic interactions between the positive and negative charges deep in the protein, away from water

Front 24

How is the quaternary structure formed?

Back 24

The quaternary structure results from the ways in which multiple polypeptide subunits bind together and interact. This level of structure adds to the three-dimensional shape of the finished protein

Front 25

What is crucial to the functioning of some proteins?

Back 25

Shape because the combination of attractions, repulsions, and interactions determines the right fit

Front 26

Look at figure 3.10

Back 26

:)

Front 27

What can change the shape of proteins?

Back 27

Changes in temperature, pH, salt concentrations, and oxidation or reduction conditions

Front 28

What is denaturation?

Back 28

This loss of a protein’s normal three-dimensional structure

Front 29

What are chaperonins?

Back 29

They are specialized proteins that help keep other proteins from interacting inappropriately with one another

Front 30

Look at figure 3.12

Back 30

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Front 31

What are carbohydrates?

Back 31

They are carbon molecules with hydrogen and hydroxyl groups.They act as energy storage and transport molecules. They also serve as structural components

Front 32

What are the four major categories of carbohydrates?

Back 32

Monosaccharides
Disaccharides, which consist of two monosaccharides
Oligosaccharides, which consist of between 3 and 20 monosaccharides
Polysaccharides, which are composed of hundreds to hundreds of thousands of monosaccharides

Front 33

The general formula for a carbohydrate monomer is ___________

Back 33

Multiples of CH2O, maintaining a ratio of 1 carbon to 2 hydrogens to 1 oxygen

Front 34

What happens during polymerization?

Back 34

It is a condensation reaction where water is removed

Front 35

What monosaccharide do all living cells have?

Back 35

Glucose (C6H12O6)

Front 36

How does glucose exist?

Back 36

Glucose exists as a straight chain and a ring, with the ring form predominant. The two forms of the ring, a-glucose and b-glucose, exist in equilibrium when dissolved in water

Front 37

Look at figure 3.13 and 3.14

Back 37

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Front 38

Monosaccharides are bonded together covalently by condensation reactions. What are these bonds called?

Back 38

Glycosidic linkages

Front 39

Look at figure 3.15

Back 39

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Front 40

Describe oligosaccharides

Back 40

Oligosaccharides contain more than two monosaccharides.
Many proteins found on the outer surface of cells have oligosaccharides attached to the R group of certain amino acids, or to lipids.

Front 41

What are polysaccharidess?

Back 41

Polysaccharides are giant polymers of monosaccharides connected by glycosidic linkages

Front 42

What is cellulose?

Back 42

Cellulose is a giant polymer of glucose joined by b-1,4 linkages

Front 43

What is starch?

Back 43

Starch is a polysaccharide of glucose with a-1,4 linkages.

Front 44

Look at figure 3.16

Back 44

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Front 45

Carbohydrates are modified by the addition of ______

Back 45

Functional groups

Front 46

Look at figure 3.17

Back 46

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Front 47

Why are lipids insoluble in water?

Back 47

This insolubility results from the many nonpolar covalent bonds of hydrogen and carbon in lipids

Front 48

What are the roles for lipids in organisms?

Back 48

Energy storage (fats and oils)
Cell membranes (phospholipids)
Capture of light energy (carotinoids)
Hormones and vitamins (steroids and modified fatty acids)
Thermal insulation
Electrical insulation of nerves
Water repellency (waxes and oils)

Front 49

What are the roles of fats and oils in the organism?

Back 49

Fats and oils store energy. Fats and oils are triglycerides, composed of three fatty acid molecules and one glycerol molecule

Front 50

Look at figure 3.18

Back 50

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Front 51

Saturated fatty acids _____

Back 51

Have only single carbon-to-carbon bonds and are said to be saturated with hydrogens

Front 52

Unsaturated fatty acids _____

Back 52

Have at least one double-bonded carbon in one of the chains —the chain is not completely saturated with hydrogen atoms

Front 53

Look at figure 3.19

Back 53

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Front 54

Phospholipids have ____

Back 54

Two hydrophobic fatty acid tails and one hydrophilic phosphate group attached to the glycerol

Front 55

Look at figure 3.20

Back 55

:)

Front 56

What are carotenoids?

Back 56

Carotenoids are light-absorbing pigments found in plants and animals

Front 57

Look at figure 3.21

Back 57

:)

Front 58

What are steroids?

Back 58

Steroids are signaling molecules. Steroids are organic compounds with a series of fused rings

Front 59

Look at figure 3.22

Back 59

:)

Front 60

What are vitamins?

Back 60

Small molecules not synthesized by the body—must acquire in diet

Front 61

What are waxes?

Back 61

Waxes are highly nonpolar molecules consisting of saturated long fatty acids bonded to long fatty alcohols

Front 62

What is a fatty alcohol?

Back 62

A fatty alcohol is similar to a fatty acid, except for the last carbon, which has an —OH group instead of a —COOH group