chapter 3

Question 1

functional groups

Answer 1

Small groups of atoms that are attached to larger molecules giving them specific chemical properties

Question 2

isomers

Answer 2

substances with the same molecular or empirical formula but can exist in different forms

Question 3

structural isomers

Answer 3

substances that have the same molecular or empirical formula but have different carbon skeletons

Question 4

stereoisomers

Answer 4

substances with the same molecular or empirical formula and carbon skeleton, but differ in the arrangement of groups

Question 5

enantiomers

Answer 5

stereoisomers that are mirror images to each other

Question 6

Chiral molecules

Answer 6

a substance that has mirror image versions

Question 7

State the four basic groups in macromolecules

Answer 7

carbohydrates
nucleic acids
protein
lipids

Question 8

polymer

Answer 8

A long molecule built by linking together a large amount of small chemical subunits called monomers
- macromolecules are polymers

Question 9

dehydration reaction or condensation reaction

Answer 9

the formation of covalent bonds between monomers but removing a OH- molecule from one and a H+ molecule from another, thus forming a water molecule

Question 10

hydration reaction

Answer 10

the breaking of covalent bonds between monomers by adding a H+ molecule to one and a Oh_ molecule to another,

Question 11

Carbohydrates

Answer 11

compounds containing carbon, hydrogen and oxygen atoms in the molar ratio 1:2:1

Question 12

What feature of carbohydrates makes them suitable for energy storage?

Answer 12

the release of energy when oxidation occurs due to carbon hydrogen bonds

Question 13

Monosaccharides

Answer 13

the most simple form of carbohydrates

Question 14

what is the most 6-carbon monosaccharide and what is its function?

Answer 14

Glucose, it is a storage molecule.

- it exits in two forms alpha and beta glucose.

Question 15

State glucoses:

• structural isomer
• stereoisomer

Answer 15

the structural isomer of glucose is fructose

the stereoisomer of glucose is galactose

Question 16

disaccharide

Answer 16

a substance made from linking two monosaccharides together

Question 17

transport forms

Answer 17

disaccharides that act as glucose reservoirs as enzymes cannot break the bonds between the sub- units to make use of the glucose

Question 18

Name the two sub- units the come together to make the following transport sugars:

• sucrose
• lactose

Answer 18

sucrose: glucose and fructose
lactose: glucose and galactose

Question 19

polysaccharides

Answer 19

long polymers that are made of monosaccharides joined by dehydration reactions

Question 20

glycogen

Answer 20

a polysaccharide made entirely of alpha glucose, that has storage functions

Question 21

how do glucose molecules link?

Answer 21

carbon 1 of one molecule links with carbon 4 of another

1 to 4 linkages

Question 22

cellulose

Answer 22

polysaccharide entirely made of beta glucose and has structural functions( make tough fibres)

Question 23

state the two types of nucleic acids

Answer 23

DNA

RNA

Question 24

State the functions of RNA

Answer 24

• carries information
• responsible for protein synthesis
  it is involved in control of gene expression

Question 25

What are the monomers of nucleic acids?

Answer 25

nucleotides

Question 26

State components of Nucleotides

Answer 26

- pentose - 5 sugar group ( ribose or deoxyribose) - organic nitrogenous base

Question 27

Phosphodiester bonds

Answer 27

bonds that form between nucleotides , through dehydration reactions between phosphates and sugars

Question 28

Name the two groups of nitrogenous bases

Answer 28

- purines | - pyrimidines

Question 29

purines

Answer 29

large double ring molecules( Adenine and guanine)

Question 30

pyrimidines

Answer 30

Single ring molecules ( thymine , uracil, thymine)

Question 31

What is the function of DNA

Answer 31

It stores genetic information

Question 32

Chromosomes

Answer 32

structures that form in eukaryotes when DNA is complexed with protein

Question 33

Name the different types of RNA and their functions

Answer 33

- mRNA ( carries information) - rRNA ( Part of the ribosome) - tRNA ( carries amino acids)

Question 34

Give the defining characteristics of RNA

Answer 34

- uses uracil instead of thymine - singe stranded - has sugar ribose

Question 35

Give the defining characteristics of DNA

Answer 35

- double stranded | - has sugar deoxyribose

Question 36

The basic components of an amino acid

Answer 36

- an amino group - carboxyl group - a R group

Question 37

Name and describe the five common amino acid groups groups

Answer 37

- non polar ( contain the R groups CH2 and CH3) leucine - polar uncharged ( R groups contain OH or oxygen) threonine - Charged amino acids ( R groups containing acids or bases that ionise) glutamic acid - Aromatic ( R group contains organic carbon ring with alternating single and double bonds)

Question 38

Peptide bonds

Answer 38

covalent bond that links two amino acids ( forms between the amino group of of one molecule and the carboxyl group of another molecule)

Question 39

polypeptide

Answer 39

long unbranched chains that are made of amino acids joined by peptide bonds

Question 40

Describe the levels of protein structure

Answer 40

- primary structure ( amino acid sequence ) - secondary structure( coils and sheets) - tertiary structure ( three dimensional shape) - quaternary structure ( the arrangement of the protein sub- units )

Question 41

Name and describe the two types of secondary structure

Answer 41

- Alpha helix ( coiled into a spiral shape) | - beta helix ( regions of peptide lined next to each other to form a planar structure)

Question 42

what drives a protein to its tertiary structure

Answer 42

hydrophobic expulsion of non polar R groups

Question 43

Van der Waal

Answer 43

attractive force between non polar interior of proteins

Question 44

Subunits of a protein

Answer 44

individual chains formed by the association of polypeptide chains

Question 45

motifs

Answer 45

similarities between otherwise dissimilar proteins

Question 46

domains

Answer 46

functional units within a larger structure | substructure within the tertiary structure of proteins'

Question 47

chaperone proteins

Answer 47

proteins that help other proteins fold properly

Question 48

denaturation

Answer 48

process whereby proteins my change structure or unfold due to a change in the environment

Question 49

What factors can lead to denaturation?

Answer 49

change in: - pH - temperature - ionic composition of the surrounding solution

Question 50

what is a result of the denaturation of proteins?

Answer 50

Denatured proteins are biologically inactive

Question 51

renaturation

Answer 51

the spontaneous refolding of portions of a protein due to the reestablishment of the normal environment of a protein

Question 52

Give the defining characteristic of lipids

Answer 52

they are insoluble in water

Question 53

triglyceride

Answer 53

structure of a fat molecule( three fatty acids each attached to one carbon on a glycerol molecule)

Question 54

saturated

Answer 54

having the maximum number of hydrogen atoms , each carbon molecule is bonded to two hydrogen atoms

Question 55

unsaturated

Answer 55

when there are double bonds between two or more pairs of successive carbon atoms in fatty acids

Question 56

what makes lipids excellent energy storage molecules

Answer 56

the ratio of energy storing C- H bonds is more than twice that of carbohydrates

Question 57

Describe the structure of phospholipids

Answer 57

- glycerol backbone - two fatty acids - one phosphate group (polar head and two long non polar tails)

Question 58

What is within the interior of phospholipid bilayers

Answer 58

- hydrophobic regions - non polar regions - fatty acid tails