biological molecules

Question 1

What is a ‘polar’ molecule?

Answer 1

A molecule that has an uneven distribution of electron density

Question 2

What part of the water molecule has a partial negative charge?

Answer 2

oxygen atom

Question 3

What part of the water molecule has a partial positive charge?

Answer 3

Hydrogen atoms

Question 4

Since water is a polar molecule, what does it attract?

Answer 4

Other polar molecules

Question 5

Why is it important for living organisms that water is a good solvent?

Answer 5

Allows chemical reactions to take place in solution
It can act as a transport medium
(blood transports many substances) (water transports dissolved substances in the xylem and phloem of plants)

Question 6

What does oxygen in water become attracted to when mixed with sodium chloride?

Answer 6

Sodium
(oxygen is partially negative and sodium is positive, therefore they attract each other)

Question 7

What is cohesion?

Answer 7

Cohesive force is the property of like molecules sticking together, being mutually attractive

Question 8

What is high surface tension?

Answer 8

cohesion between the water molecules at the surface produces surface tension
(allows insects to walk on water)

Question 9

What does cohesion enable in living organisms?

Answer 9

Allows water to flow, very important for transmitting substances

Question 10

What does it mean if water has a high specific heat?

Answer 10

A large amount of energy is needed to raise the temperature
Good for organisms that live in water because the temperature wont raise

Question 11

What does it mean if water has a high latent heat?

Answer 11

A large amount of energy is needed to change it from liquid to gaseous state
It takes a large amount of energy for sweat to evaporate taking temperature down more efficiently

Question 12

Why is important that water transparent?

Answer 12

Because light needs to go through for photosynthesis

Question 13

Why is it important that ice is less dense than water?

Answer 13

Because ice acts as an insulator

Question 14

What are the 4 most common elements in living things?

Answer 14

Hydrogen
Nitrogen
Carbon
Oxygen

Question 15

What are the 3 elements in carbohydrates?

Answer 15

Carbon
Oxygen
Hydrogen

Question 16

Whats the basic formula for carbohydrates?

Answer 16

(CH2O)n

Question 17

How many carbon atoms does Triose have?

Answer 17

3 Carbon atoms

Question 18

How many carbons does pentose have?

Answer 18

5 carbon atoms

Question 19

How many sugars does Hexose have?

Answer 19

6 carbon atoms

Question 20

What are the two different isomers of glucose?

Answer 20

alpha and beta

Question 21

Whats the difference between alpha and beta glucose?

Answer 21

Different structural formula (learn it!)

Question 22

What are the main functions of monosaccharides?

Answer 22

Energy in respiration
Building blocks for larger molecules

Question 23

What are disaccharides?

Answer 23

2 monosaccharide units joined together

Question 24

What is hydrolosis?

Answer 24

water splitting
(A chemical breakdown of a compound due to reaction with water)

Question 25

What molecules are formed when condensation reaction occurs?

Answer 25

water molecule

Question 26

What are polysaccharides?

Answer 26

Large complex molecules called polymers, contain large numbers of monosaccharides linked by glycosidic bonds

Question 27

What is a monomer?

Answer 27

Single repeating unit of a polymer

Question 28

What is a polymer?

Answer 28

A large molecule comprising repeated units (monomers) binded together

Question 29

Role of Magnesium in living organisms

Answer 29

constituent of chlorophyll, required for photosynthesis & leaves turn yellow if in short supply

Question 30

Role of calcium in living organisms

Answer 30

Important for the structural component of bones and teeth & provides strength.

Question 31

Roles of Phosphate in living organisms

Answer 31

Used for making neucleortides, ATP phospholipids (found in membranes)

Question 32

Role of iron in living organisms

Answer 32

Constituent of hemoglobin (which carries oxygen in red blood cells). lack of iron leads to anemia

Question 33

What is an organic molecule?

Answer 33

Molecules that contain carbon

Question 34

What is an inorganic molecule?

Answer 34

Molecules that usually do not contain carbon

Question 35

What two monosaccharides make up (disaccharide) maltose?

Answer 35

Glucose+Glucose

Question 36

What two monosaccharides make up (disaccharide) sucrose?

Answer 36

Glucose+Fructose

Question 37

What two monosacchardies make up (disaccharide) Lactose?

Answer 37

Glucose+Glactose

Question 38

What are the functions of disaccharides?

Answer 38

Provide energy and help wit the absorption of nutrients

Question 39

Why is starch and glycogen used for storage instead of glucose?

Answer 39

Insoluble so they have no osmotic effect They cannot diffuse out of the cell They are compact molecules and can be stored in a small space They can carry a lot of energy in their C-C & C-H bonds

Question 40

Where is starch found?

Answer 40

Starch is the main store of glucose in plants.

Question 41

What are 4 types of polysaccharides?

Answer 41

Starch Glucose Cellulose Chitin

Question 42

What is starch made from?

Answer 42

Two polymers of alpha glucose bonding in different ways forming amylose and amylopectin

Question 43

Differences between amylose and amylopectin 1

Answer 43

Amylose is straight chain polymer Amylopectin is a branched chain polymer

Question 44

Differences between amylose and amylopectin 2

Answer 44

Amylase has alpha-1,4-glycosidic bonds forming between the first carbon C1 on one monomer and the fourth carbon C4 on an adjacent monomer. Amylopectin has alpha-1,6 glycosidic bonds.

Question 45

What is the function of cellulose?

Answer 45

To make plant cell walls Provide structure

Question 46

What is the structure of cellulose?

Answer 46

Consists of many long, parallel chains of beta-1,4-glycosidic bonds, the beta link rotates adjacent glucose molecules by 180°

Question 47

What are lipids made up of?

Answer 47

Carbon, Hydrogen and Oxygen.

Question 48

What do Phospholipids contain?

Answer 48

Phosphorus in a phosphate group.

Question 49

Do lipids have a charge?

Answer 49

They have no charge (non-polar) an are insoluble in water.

Question 50

What are Triglycerides formed of?

Answer 50

One molecule of glycerol and three molecules of fatty acids.

Question 51

What same molecule is in every lipid?

Answer 51

Glycerol.

Question 52

What are the products of lipid hydrolysis?

Answer 52

Glycerol and fatty acids.

Question 53

How do you know when the fatty acid is saturated?

Answer 53

Only single carbon-carbon bonds.

Question 54

How do you know when the fatty acid is unsaturated?

Answer 54

If any carbon-carbon bond is not a single bond, the molecule is unsaturated.

Question 55

Function of Triglycerides

Answer 55

Energy reserves, Thermal insulation, Protection, Producing metabolic water.

Question 56

Function of phospholipids?

Answer 56

Structural, Electrical insulation.

Question 57

Function of waxes?

Answer 57

Waterproofing

Question 58

What metabolic water mean?

Answer 58

Water released in the cell of an organism by its metabolic reactions.

Question 59

What can lipids dissolve in?

Answer 59

Organic solvents e.g. alcohol and propanone.

Question 60

Triglycerides. What happens when fatty acids join glycerol by condensation reaction?

Answer 60

Three molecules of water are removed and ester bonds are formed between the glycerol and fatty acids

Question 61

What are ester bonds?

Answer 61

An oxygen atom joining two carbon atoms.

Question 62

Why is phospholipids a special type of lipids?

Answer 62

polar head is hydrophillic non-polar tails are hydrophobic