Learning Objectives

Question 1

Describe the components of an Atom

Answer 1

Electrons
Neurons
Proton

Question 2

Differentiate between an element, a molecule and a compound

Answer 2

-Elements have only one kind of atom

-A molecule is a neutral particle that is held together by covalent bonds.

-A compound has more than one element chemically bonded

Question 3

List the elements of life.

Answer 3

Carbon (C), hydrogen (h), oxygen (0), and nitrogen (N)

Question 4

Define an isotope

Answer 4

Members of a family of an element that all have the same number of protons but different number of neutrons

Question 5

Differentiate between covalent bonds and non-covalent bonds

Answer 5

chemical bonds formed when two atoms share electrons between themselves.

do not have a shared pair of electrons; instead, atoms attract opposite charges.

Question 6

Differentiate between polar and non-polar covalent bonds

Answer 6

Polar- chemical bond where two atoms unequally share a pair of electrons

Non polar- chemical bond where two atoms share a pair of electrons with each other.

Question 7

Describe:
-ionic

-hydrogen

-van-der Waals forces

Answer 7

-A bond formed by the electrostatic attraction of two oppositely charged ions

-A hydrogen atom is weakly shared between two electronegative atoms

-The weakest interaction due to the motion of electrons

Question 8

What is matter?

Answer 8

Any substance that has mass

Question 9

What is an element?

Answer 9

A substance whose atoms all have the same numbers of protons

Question 10

What is a compound?

Answer 10

Has more than one elements chemically bonded

Question 11

Discuss the four emergent properties of water

Answer 11

Cohesive behavior
- cohesion and adhesion
- surface tension

Ability to moderate temperature
- high specific heat
- stabilizing temperature

Expansion upon freezing
- floating of ice on liquid water

Versatility as a solvent

Question 12

Explain what pH is in relation to H+ and OH- ions

Answer 12

pH measures the balance of H+ and OH- ions

More H+ ions = acidic (pH<7)

More OH- = basic (pH>7)

Equal H+ and OH- ions = neutral (pH = 7)

Question 13

Explain acidic and basic properties in relation to pH

Answer 13

Acids have a pH below 7
High concentrations of H+ ions
Sour taste and corrosive
Eg. Hydrochloric acid

Basics have a pH above 7
High concentration of OH- ions ( more hydroxide ions than hydrogen ions )
Bitter taste and slippery feel
Eg. Sodium hydroxide

Question 14

Explain why organisms are sensitive to changes in pH and temperatures

Answer 14

can directly affect the structure and function of biological molecules, especially protein and enzymes

Question 15

Discuss the role of buffers in relations to pH

Answer 15

They allow biological fluids to maintain a relatively constant pH despite the addition of acids or bases

Referred to as H+ “ sponges” because they remove H+ from solution when levels increase and release when levels fall.

Question 16

Define organic chemistry

Answer 16

The study of the structure properties, composition, reactions and preparation of carbon containing compounds

Question 17

Define hydrocarbons

Answer 17

An organic compound consisting entirely of hydrogen and carbon

Question 18

Define isomers

Answer 18

Organic compounds with the same molecular formula but different structures and properties

Question 19

Types of isomers

Answer 19

Structural isomers
- different covalent arrangements of their atoms

Cis-trans isomers
- the same covalent bonds but differ in spatial arrangements around a double bond

Enantiomers
- are mirror images of each other

Question 20

different types of functional groups on organic molecules

Answer 20

• Hydroxyl
• carboxyl
• carbonyl
• Amino
• sulfhydryl
• phosphate
• methyl

Question 21

Discuss the functions of carbohydrates

Answer 21

Functions:
- fuel source - important source of energy when oxidized
- energy storage - starch in plants: glycogen in animals
- structural - cell walls in plants (cellulose) and bacteria ( peptidoglycan ); cell wall of fungi and in exoskeleton (chitin)

Question 22

Discuss the basic structures of carbohydrates

Answer 22

Monosaccharides
- glucose
- fructose
- galactose

Disaccharides
- sucrose
- lactose
- maltose

Polysaccharides
- starch
- glycogen
- cellulose

Question 23

Explain monosaccharides, disaccharides and polysaccharides

Answer 23

Monosaccharides - the simplest form of carbohydrates, consisting of single sugar units

Disaccharides - composed of two monosaccharide units linked by a glycosidic bond.

Polysaccharides - long chains of monosaccharide units. They often function as recognition signals on cell surfaces

Question 24

Discuss the functions of lipids

Answer 24

Fuel source - important energy source when oxidized

Energy storage - plants store oil in seeds while humans and other mammals store fats and oils in adipose tissues

Structural - phospholipids, cholesterol and glycolipids in cell membranes

Cell communication - acts as ‘markers’ for cell recognition and communication

Hormones - many act as hormones ( steroid hormones )

Question 25

Distinguish between saturated and unsaturated fatty acids

Answer 25

saturated fats
-there are no double bonds between carbon atoms composing a chain
- the structure is saturated with hydrogen
- most animal fats are saturated and solid at room temperature

Unsaturated fats
- has one or more double bonds, with one fewer hydrogen atom on each double-bonded carbon
- plant fats and fish are unsaturated and liquid at room temperature

Question 26

What type of chemical bond occurs between 2 atoms with an electronegativity difference larger than 1.9?

Answer 26

Ionic bond

Question 27

Name a monomer of a carbohydrate

Answer 27

Monosaccharide

Question 28

Which functional groups are present in carbohydrates?

Answer 28

Carbonyl and hydroxyl

Question 29

What is the difference between an Aldose and a Ketose?

Answer 29

Aldose contains an aldehyde group, consisting of Carbon, hydrogen and oxygen ( CHO )

Ketose contains a keytone group, consisting of Carbon and oxygen ( CO)

Question 30

What is glycogen?

Answer 30

A form of glucose, a main source of energy that your body stores primarily in your liver and muscles.