Unit 1 Chapter 2: Basic Chem + Functional Groups

Question 1

Forms of an element with different numbers of neutrons are called?

Answer 1

Isotopes

Question 2

The atoms that are most abundant in living cells are?

Answer 2

H,C, N, O, Na, Mg, P, S, Cl

Question 3

List bond strengths in order

Answer 3

covalent>hydrogen/ionic>hydrophobic>van der waals

Question 4

How does a covalent bond occur

Answer 4

sharing of electrons, when attractions overcome repulsions

Question 5

What are hydrogen/ionic bonds

Answer 5

attraction of opposite charges

Question 6

What are hydrophobic interactions

Answer 6

exclusion of non-polar molecules from water

Question 7

What are van der waal’s attractions

Answer 7

interactions due to fluctuating electrical charges

Question 8

What is bond energy

Answer 8

the energy needed to separate 2 bonded or interacting atoms under physiological conditions

Question 9

Where do electrons in a polar covalent bond spend most of their time

Answer 9

close to the nucleus of the more electronegative atom

Question 10

What is Adhesion

Answer 10

attraction between unlike molecules ie. water and a surface (force up)

Question 11

What is cohesion

Answer 11

attraction between like molecules ie. water and itself (force down)

Question 12

Which form of water is MORE dense

Answer 12

liquid, because ice forms a crystal lattice with gaps in between but liquid water does not

Question 13

Does hydrolysis release or absorb energy

Answer 13

releases

Question 14

Acids are…

Answer 14

proton donors

Question 15

Bases are…

Answer 15

proton acceptors

Question 16

Each increase/decrease in pH is how many times more basic/acidic

Answer 16

10 times

Question 17

Buffers

Answer 17

• minimize changes in pH

- most are weak acids

Question 18

What is the pH of solution inside cells

Answer 18

about 7

Question 19

How many hydrogen bonds does each water molecule form as water freezes

Answer 19

4

Question 20

What is Energy

Answer 20

the capacity to do work or supply heat

Question 21

The kinetic energy of molecular motion is called

Answer 21

thermal energy

Question 22

Temperature is

Answer 22

the average kinetic energy per molecule

Question 23

Heat is

Answer 23

the transfer of thermal energy

Question 24

The first law of thermodynamics is

Answer 24

energy cannot be created or destroyed, only transferred and transformed

Question 25

The second law of thermodynamics is

Answer 25

the universe tends towards disorder

Question 26

Reactions are spontaneous if (2 reasons)

Answer 26

1. products have lower potential energy than reactamts (exo)

2. the products are less ordered than reactants(positive entropy)

Question 27

For a spont. reaction free energy is

Answer 27

negative

Question 28

An Amino (funt.group) is (+properties)

Answer 28

• NH2

- acts as a base

Question 29

A Carbonyl (funt.group) is (+properties)

Answer 29

• aldehydes (end)
• ketones(middle)
• double bond O
• aldehydes react with compounds to make large molecules

Question 30

A Carboxyl (funt.group) is (+properties)

Answer 30

• carboxylic acids
• double bond O, OH
• act as acids

Question 31

A Hydroxyl (funt.group) is (+properties)

Answer 31

• alcohols
• OH
• highly polar, so makes compounds more soluble in H2O
• sometimes acts as a weak acid

Question 32

A Phosphate (funt.group) is (+properties)

Answer 32

• when several of these are linked together, breaking P-O bonds releases a lot of energy
• P double bond O and 3 other Os

Question 33

A Sulphydryl (funt.group) is (+properties)

Answer 33

• SH
• thiols
• can form disuphides (S-S) when present in proteins which contribute to protein structure