Molecular Building Blocks of Life

Question 1

What are the 3 types of bonds?

Answer 1

Ionic, Covalent, Hydrogen.

Question 2

Water (H2O) has a high heat capacity. What does this mean?

Answer 2

It can absorb a lot of heat before changing temperature.

Question 3

What kind of molecules are hydrophilic and dissolve well in water?

Answer 3

Charged particles such as ions or polar molecules.

Question 4

This is a unit of measurement in chemistry and means 6.023 X 10^23 individual molecules.

Answer 4

The mole.

Question 5

The Molar is a measure of concentration and means 1 mole of substance in how much solution?

Answer 5

1 litre, i.e. 1 Molar of glucose is 1 litre of solution containing 1 mole of glucose.

Question 6

What kind of reactions release more energy than they absorb?

Answer 6

Exergonic.

Question 7

If a solution become more acidic, what happens to its pH?

Answer 7

It goes down.

Question 8

What are the 4 main organic molecules in the human body?

Answer 8

Carbohydrates, lipids, proteins, nucleic acids.

Question 9

What are the 3 main kinds of reaction that occur in the human body?

Answer 9

Decomposition or catabolic, synthesis or anabolic, and exchange reactions.

Question 10

What is the role of catalysts in reactions?

Answer 10

They speed up reactions by lowering the activation energy required.

Question 11

What organic functional group can release hydrogen ions if pH gets too high?

Answer 11

Carboxylic acid group.

Question 12

What organic functional group can accept hydrogen ions if pH gets too low?

Answer 12

Amine group.

Question 13

What is the importance of hydroxyl groups?

Answer 13

They can release hydrogen ions if pH gets too high and they enable dehydration synthesis to combine molecules.

Question 14

What is the importance of phosphate groups?

Answer 14

They store energy in high energy bonds and can form chains of molecule, e.g. in nucleic acids.

Question 15

Carbohydrates contain carbon, hydrogen, and oxygen in what ratio?

Answer 15

1:2:1.

Question 16

What are the functions of carbohydrates?

Answer 16

They are a source of energy, they form a part of nucleic acids, and they are form cellular ID molecules.

Question 17

Glycogen is an example of what kind of carbohydrate?

Answer 17

Polysaccharide.

Question 18

What non-polar molecules serve as dense energy sources and form a crucial part of the cell membrane?

Answer 18

Lipids.

Question 19

What are the types of lipid?

Answer 19

Fatty acids, glycerides, conjugated lipids, steroids, and eicosanoids.

Question 20

Fatty acids are long chains of carbon and hydrogen with what functional group at one end?

Answer 20

Carboxylic acid group.

Question 21

Fatty acids combine with gylcerol to form what?

Answer 21

Triglycerides.

Question 22

What are the functions of triglycerides?

Answer 22

Energy storage, insulation, protection (cushioning).

Question 23

What is the most abundant kind of organic molecule in the human body?

Answer 23

Proteins.

Question 24

What are the building blocks of proteins?

Answer 24

Amino acids.

Question 25

When amino acids are joined together they release a water (H2O) molecule. What kind of reaction is this?

Answer 25

Dehydration synthesis.

Question 26

What are the main functions of proteins?

Answer 26

Structure and support, movement, transport of molecules, buffering (resisting pH changes), catalytic (enzymes), signalling (as hormones), defense (e.g. antibodies).

Question 27

All amino acids have both an amine group and carboxylic acid group, but what part makes them unique?

Answer 27

The side chain.

Question 28

What are the four structural levels of proteins?

Answer 28

1. Primary (amino acid sequence) 2. Secondary (α-helices and β-sheets maintained by hydrogen bonds) 3. Tertiary (final 3 dimensional shape of a polypeptide) 4. Quaternary (several polypeptides combined)

Question 29

What are the characteristics of enzymes?

Answer 29

1. They are specific for one kind of reaction 2. They can be saturated (limit where reaction rate doesn't increase) 3. They can be regulated, i.e. switched off and on.

Question 30

What are the 2 main classes of nucleic acid?

Answer 30

DNA and RNA.

Question 31

Nucleic acids consist of a nitrogenous base, a sugar group, and what else?

Answer 31

A phosphate group.

Question 32

What are the 5 nitrogenous bases that are in nucleic acids?

Answer 32

Adenine, guanine, cytosine, thymine (DNA only), uracil (RNA only.

Question 33

What is the function of DNA?

Answer 33

Stores information in genes.

Question 34

What is the function of RNA?

Answer 34

Transcribes genes and makes proteins.