Life at the Cellular Level 2

Question 1

What are the 10 elements that are normally found in structural parts of organisms?

Answer 1

H, C, N, O, Na, P, S, Cl, K and Ca

Question 2

How many trace elements are needed in small amounts?

Answer 2

12

Question 3

What are 99% of our cells composed of?

Answer 3

H, N, C and O

Question 4

What are H, N, C and O found in 99% of our cells?

Answer 4

Because they are the lightest atoms which can form the strongest bonds (H forms 1, O forms 2, N forms 3 and C forms 4)

Question 5

Why does carbon form the bases of all biomolecules?

Answer 5

Because it is so versitle, being able to form 4 bonds

Question 6

What defines a molecules function?

Answer 6

Its functional group

Question 7

What are some functional groups?

Answer 7

Hydroxyl (polar, hydrogen bonds, linkage by dehydration)

Aldehyde (C=O very reactive)

Keto (C=O very reactive)

Carboxyl (hydrogen bonding, polar)

Amide (hydrogen bonds)

Question 8

What does the hydroxyl functional group look like?

Question 9

What does the aldehyde functional group look like?

Question 10

What does the keto functional group look like?

Question 11

What does the carboxyl functional group look like?

Question 12

What does the amide functional group look like?

Question 13

Why is the polarity of carbon critical to function?

Answer 13

C-C and C-H are relatively stable or share e^- evenly

C-O or C-N o C-functional group are highly polar which allows carbons bond reactivity

Question 14

Does funcition also depend on how groups are arranged in a molecule?

Answer 14

Yes

Question 15

What is configuration?

Answer 15

The final arrangement of atoms in a molecule

Question 16

Why is C=C a rigid conformation?

Answer 16

Because cannot move freely around a double bond so can only have two distinct configurations

trans

cis

Question 17

How do you convert between trans and cis configurations?

Answer 17

By breaking and reforming the bonds

Question 18

C an be a chiral centre, what are the two forms?

Answer 18

Laevo (left handed)

Dextro (right handed)

Question 19

Is the difference between laevo and dextro important?

Answer 19

Yes, all proteins are made from L-amino acids

Question 20

What is conformation?

Answer 20

The precise arrangement of atoms in a molecule

Question 21

What is a property of bonds that can rotate freely?

Answer 21

They can form many different conformations without breaking and reforming bonds

Question 22

What dictates how freely bonds can rotate?

Answer 22

Interaction of groups, certain conformations are favoured

Question 23

What are the five chemical reactions of life?

Answer 23

Redox reactions

Making and breaking C-C bonds

Internal rearrangement

Group transfers

Condensation and hydrolysis reactions

Question 24

What are redox reactions?

Answer 24

Redox reactions involve oxidation (loss of electrons) or reduction (gain of electrons)

Question 25

Is every reduction accompanied by oxidation and vice versa?

Answer 25

Yes

Question 26

What is condensation?

Answer 26

Addition reaction that produces water

Question 27

What is hydrolysis?

Answer 27

Reaction involving breaking a bond in a molecule using water

Question 28

What are proteins?

Answer 28

Polymers of amino acid monomers linked by peptide bonds

Question 29

What is a monomer?

Answer 29

A molecule that is able to bond in a long chain

Question 30

What is a polymer?

Answer 30

A substance whose molecular structure is built up from a large number of similar units bonded together

Question 31

What are nucleic acids?

Answer 31

Polymers of nuceotide monomers linked 3', 5'-phosphodiester bonds

Question 32

What does a diagram of a nucleotide look like?

Question 33

What are the two kinds of bases in nucleic acids?

Answer 33

Pyrimidines (flat single rings such as cytosine, thymine and uracil) Purines (flat double ring such as adenine and guanine)

Question 34

What does a diagram showing the conversion of a base to a nucleotide look like?

Question 35

What does the flat planer structure of bases allow DNA to do?

Answer 35

Form the double helix

Question 36

What is the reason behind base pairing?

Answer 36

A and T can form two bonds G and C can form three bonds

Question 37

How is RNA different form DNA

Answer 37

Single stranded Ribose sugar instead of deoxyribose Uracil (U) base replaces thymine (T)

Question 38

How do double stranded segments of RNA form?

Answer 38

Sequences of RNA nucleotide pair with one another

Question 39

What are polyaccharides?

Answer 39

Polymers of sugar monomers linked by glucosidic bonds

Question 40

What are examples of polysaccharides?

Answer 40

Starch and glycogen

Question 41

Why is D-glucose terms a reducing sugar?

Answer 41

Linear form containing an aldehyde can be oxidised

Question 42

What are properties of glycose polymers?

Answer 42

Formed from condensation reaction between glucose monomers Monomers are in cyclic form except the end monomer which is linear and known as a reducing end

Question 43

What are lipids?

Answer 43

Molecules that contain hydrocarbons and is souble in nonpolar solvents

Question 44

What do saturated and unsaturated lipids look like?

Question 45

What do more double carbon bonds do to a lipid?

Answer 45

Molecule becomes less linear and more bent

Question 46

What are some classes of lipids?

Answer 46

Triacylglycerides Phopholipids

Question 47

What are properties of triacylglyderides?

Answer 47

Act as storage lipids, releasing a lot of energy when broken down Non polar Three fatty acid chains linked to glycerol

Question 48

What are properties of phospholipids?

Answer 48

Have a hydrophilic head group attracted to glycerol, making them polar Tail composed of two hydrophobic fatty acid chains