Biological Molecules 3

Question 1

What are the two Nucleic acids?

Answer 1

DNA and RNA

Question 2

What are the levels of organisation for nucleic acids?

Answer 2

Nucleotide, dinucleotide, polynucleotide

Question 3

What is the DNA nucleotide made up of?

Answer 3

A phosphate group, a pentose (five carbon) deoxyribose sugar, nitrogenous base.

Question 4

what are the four bases in a DNA nucleotide?

Answer 4

Adenine, thymine, cytosine, guanine

Question 5

What is an RNA nucleotide made up of?

Answer 5

A phosphate group, a pentose ribose sugar, a nitrogenous base

Question 6

what are the bases in an RNA nucleotide?

Answer 6

Adenine, uracil, cytosine, guanine

Question 7

How are polynucleotides formed?

Answer 7

DNA and RNA are made up of many nucleotides, joined together. Nucleotide drawing together in a condensation reaction to form phosphodiester bonds

Question 8

what kind of bond is formed between nucleotides?

Answer 8

Phosphodiester bond

Question 9

What is the role of DNA?

Answer 9

Holds genetic information

Question 10

What is the function of RNA?

Answer 10

to transfer genetic information from DNA to ribosomes

Question 11

how are two polynucleotide strands held together?

Answer 11

Many hydrogen bonds

Question 12

What base does adenine pair with?

Answer 12

Thymine in DNA
uracil in RNA

Question 13

What does cytosine pair up with?

Answer 13

Guanine

Question 14

What are the differences between DNA and RNA?

Answer 14

DNA is bigger
DNA is double-stranded RNA single
DNA has deoxy ribose sugar. RNA has ribose.
DNA is very stable. RNA is not.

Question 15

Why does DNA need to be replicated?

Answer 15

Because DNA must be copied exactly so each new cell has a complete copy

Question 16

What is semiconservative DNA replication?

Answer 16

Each new DNA molecule is made up of an old polynucleotide strands and a new one

Question 17

What is step one of DNA replication?

Answer 17

Unwinding

Question 18

what is unwinding in DNA replication?

Answer 18

When DNA helix is unwound/unzipped by DNA Heli case which breaks the week hydrogen bonds between complementary base pairs. This causes the polynucleotide strands to separate.

Question 19

What is step two of DNA replication?

Answer 19

Replication

Question 20

what happens during replication in DNA replication?

Answer 20

The exposed strands act as a template for the formation of a new complementary strand. Three nucleotide within the nucleus pair up with a complimentary nucleotides on the expose DNA strands according to base pair ruling.

Question 21

what is step three of DNA replication?

Answer 21

Condensation

Question 22

What happens during condensation in DNA replication?

Answer 22

DNA polymerase catalyses the condensation reaction between adjacent nucleotides, resulting in the formation of phosphodiester bond.

This process repeat until complimentary nucleotide is formed.

Question 23

what is the step four of DNA replication?

Answer 23

Completion

Question 24

what happens during completion of DNA replication?

Answer 24

New DNA strands rewind, DNA polymerase is released. Two new identical DNA molecules are formed, each containing one parent strand and one new Strand.

Question 25

What is the semiconservative hypothesis on DNA replication?

Answer 25

double-stranded DNA contains one parental and one daughter Strand following DNA replication

Question 26

What is the Conservative hypothesis on DNA replication?

Answer 26

both parental strands stay together after DNA replication (new strands together, old strands together)

Question 27

Why is DNA not replicated as a complete molecule?

Answer 27

More likely to make a mistake, no template, so how does it know which sequence? Experiments have proven otherwise.

Question 28

What are some energy demanding cellular processes?

Answer 28

Muscle contractions (movement), DNA synthesis, cell division, synthesis of amino acids, and proteins, active transport

Question 29

What is ATP?

Answer 29

An energy carrying molecule.

Question 30

What is the structure of ATP?

Answer 30

ribose, adenine, three phosphate groups

Question 31

How does ATP work?

Answer 31

Energy stored in the covalent bonds between phosphate groups and can be released when the Bonds are hydrolysed.

Question 32

What is ATP broken down into?

Answer 32

ADP and P

Question 33

What is the P in ADP and P?

Answer 33

The inorganic phosphate in a hydrolysis reaction after ATP is broken down

Question 34

How is the reaction of ATP being broken down into ADP and P catalysed?

Answer 34

ATP hydrolase

Question 35

What does the ATP ADP cycle allow?

Answer 35

It allows energy to be stored and released as it is needed in a cell.

Question 36

What else can P be used for after the hydrolysis of ATP?

Answer 36

It can be added onto other compounds to make them more reactive. This is a Phosphorylation reaction

Question 37

What are the properties of ATP?

Answer 37

It releases energy in small, manageable amount, small soluble, and easily the fuses to the part of the cell needed, it can be easily broken down to instantly release energy, it can be used to phosphorylate and make other molecules more reactive, it is quickly remade.

Question 38

what does water consist of?

Answer 38

2 atoms of hydrogen and an oxygen, held together by covalent bonds

Question 39

why does the oxygen in water have a partially negative charge and hydrogen have a partially positive charge?

Answer 39

because the oxygen is a bigger atom and so has more protons, this attracts the electrons of the hydrogen which makes it partially negative and the hydrogen partially positive

Question 40

are hydrogen bonds strong?

Answer 40

they are relatively weak and break and reform between constantly moving water molecules

Question 41

what is hydrogen bonding?

Answer 41

when the hydrogen atoms of one water molecule are attracted to the oxygen of another

Question 42

why is water a good solvent?

Answer 42

because water is polar and is attracted to other polar substances. the water molecules cluster around these parts of a solute and help them seperate

Question 43

why is water a good medium for transport?

Answer 43

the hydrogen bonds between water molecules pulls them towards each other, so they stick together, this is cohesion water molecules are attracted to surfaces such as narrow tubes, this is adhesion

Question 44

name some instances of water as a metabolite?

Answer 44

hydrolysis of a peptide bond atp hydrolysis photosynthesis

Question 45

why is water a good cooling agent?

Answer 45

it takes lots of energy to break the hydrogen bonds between water molecules, water has a high latent heat of vaporisation meaning that it will use lots of heat energy to evaporate and become a gas (sweat)

Question 46

why is water a good buffer?

Answer 46

hydrogen bonds between water molecules absorb lots of energy, this gives it a high specific heat capacity. this means it doesn’t experience rapid temp changes and uses up lots of energy before it does. water can be used to buffer temp in the case of enzymes so they don’t denature

Question 47

What is an inorganic ion?

Answer 47

inorganic ions are ions that don’t contain carbon

Question 48

What are some important inorganic ions?

Answer 48

calcium ions, component of bones and teeth. Potassium, ions, important for osmotic balance Magnesium ions, component of chlorophyll.