U1 Lecture 2

Question 1

Define atomic charge

Answer 1

• Protons are positive (+)

- Electrons are negative (-)

Question 2

Define Ion

Answer 2

Particles with a net charge

• (+) cation
• (-) anion

Question 3

Major elements in biology

Answer 3

O (65%), C (18%), H (10%), N (3%),

- P, Ca, Na, K, and Cl make up 4%

Question 4

Define element

Answer 4

A substance that cannot be split into simpler substances by ordinary chemical means

Question 5

Define molecule

Answer 5

Assembly of atoms held together by chemical bonds

Question 6

Two types of chemical bonds

Answer 6

1. Covalent bond

2. Ionic bond

Question 7

Define covalent bonds

Answer 7

‘share’ electrons

Question 8

Define ionic bonds

Answer 8

transfer of electrons between a metal and nonmetal that forms an anion or cation

Question 9

Types of covlent bonds

Answer 9

Non-polar - ‘equal sharing

Polar - ‘unequal’ sharing

Question 10

Hydrogen bonds

Answer 10

• Weak bond in biology

- Stabilize structures

Question 11

Energy flow in reactions

Answer 11

• Breaking bonds requires energy

- Making bonds releases energy

Question 12

Define metabolism

Answer 12

The result of cell manipulation of the energy stored in chemical bonds

Question 13

Two types of energy

Answer 13

1. Potential energy - the distance between particles

2. Kinetic energy - energy of motion

Question 14

Define catalyst

Answer 14

Compounds that make reactions go faster by reducing the amount of energy required to get them started
ex: enzymes

Question 15

Define solution

Answer 15

mixture of two or more components

Question 16

Solutes and Solvents

Answer 16

Solutes are mixed in a solvent

Question 17

Define aqueous solution

Answer 17

When the solvent is water

Question 18

Polarity of water

Answer 18

Water is a polar molecule, therefore it can only bond to other polar molecules

Question 19

Define concentration

Answer 19

Amount of compound divided by Unit of volume

moles/liter

Question 20

1 mole =

Answer 20

6 x 10^23 particles

Avogadro’s number

Question 21

Define pH

Answer 21

A number expressing the acidity or alkalinity of a solution on a logarithmic scale

• 7 is neutral
• Lower numbers are acidic and higher numbers are basic
• pH = -log [H+]

Question 22

Define buffers

Answer 22

Systems that maintain the pH level in the body by donating or picking up H+ ions
“H+ sponge”

Question 23

Define organic compounds

Answer 23

A molecule that contains carbon

Question 24

Examples of Organic Compounds

Answer 24

1. Lipid - C and H
2. Carbohydrate - C, H and O
3. Protein - C, H, O and N
4. Nucleic Acid - C, H, O, N and P

Question 25

Define lipid

Answer 25

A fatty acid with a polar head and non-polar tail

Question 26

Define carbohydrate

Answer 26

Molecule with C, H and O

ex: glucose, fructose, sucrose, starches

Question 27

Define protein

Answer 27

A large molecule consisting of 1+ amino acids

Question 28

Define nucleic acids

Answer 28

A long nucleotide chain composed of phosphate groups connected to sugars and base pairs

Question 29

High energy phosphates

Answer 29

• Adenosine triphosphate (ATP) = most powerful phosphate, composed of adenine (N group), ribose (O group) and 3 phosphate (P) groups
• Adenosine dihosphate (ADP) = Adenine, ribose, and 2 phosphate groups