topic 1b more biological molecules

Question 1

DNA and RNA are both?

Answer 1

types of nucleic acid, and both carry info

Question 2

DNA (deoxyribonucleic acid) function?

Answer 2

store genetic info

Question 3

RNA (ribonucleic acid) function?

Answer 3

transfer genetic info from DNA to ribosomes. Ribosomes read the RNA to make polypeptides (translation)

Question 4

Nucleotide structure?

Answer 4

phosphate group- pentose sugaer (sugar with 5 carbon atoms) and then a nitrogen base

Question 5

what are the monomers of DNA and RNA?

Answer 5

nucleotides

Question 6

polynucleotide structure?

Answer 6

many nucleotides join together. nucleotides join up between the phosphate group of one nucleotide to the sugar of another. bond is called a phosphodiester bond- formed by a condensation reaction

Question 7

polynucleotide—- whats the chain of phosphates and sugars i known as the?

Answer 7

sugar phosphate backbone

Question 8

DNA structure?

Answer 8

double helix, polynucleotide 2 strands wind round eachother

Question 9

DNA nucleotide structure?

Answer 9

phosphate group, pentose sugar (deoxyrobise0 and a base either thymine,guanine, cytosine or adenine.

Question 10

complementary base pairing?

Answer 10

2 DNA polynucleotide strands join together by hydrogen bonds between the bases.

Question 11

RNA structure?

Answer 11

ribose sugar instead of deoxyribose . Uracil replaces thymine , 2 nucleotides form a single polynucleotide strand not a double —- differences to DNA

Question 12

why does DNA replicate?

Answer 12

DNA copies itself before cell division so that each new cell has a full amount of DNA - called semi-conservative replication because half of the strands in each new DNA molecule are from the original DNA molecule

Question 13

how is DNA replicated?

Answer 13

1. DNA helicase breaks hydrogen bonds between 2 polynucleotide strand= helix unwind.
2. each original strand acts as a template for a new one, complementary base pairing means free floating DNA are attracted to their exposed bases.
3. condensation reaction joins the nucleotide of the new strand together catalysed by the enzyme DNA polymerase- hydrogen bonds form between the bases of the new and original strands
4. each new DNA molecule contains one strand from the original DNA and one new strand

Question 14

why is energy important?

Answer 14

plants and animals need energy for biological processes to occur

Question 15

Example of how plants and animals use energy?

Answer 15

Plants= active transport- solutes to their leaves- DNA replication, cell division and protein synthesis 
Animals= active transport, DNA replication, cell division and protein synthesis

Question 16

ATP stands for?

Answer 16

adenosine triphosphate

Question 17

Respiration?

Answer 17

release of energy from glucose, cell cant get its energy directly from glucose, so In respiration it is released as ATP.

Question 18

ATP structure?

Answer 18

nucleotide base (adenine), ribose sugar and 3 phosphate groups. Known as a nucleotide derivative because its a modified form of a nucleotide

Question 19

Making and using ATP?

Answer 19

when energy needed by a cell, ATP is broken into ADP+P. = hydrolysis reaction, a phosphate bond is broken, the reaction is catalysed by the enzyme ATP hydrolase

Question 20

how is ATP resynthesized?

Answer 20

condensation reaction between ADP and P - catalysed by enzyme ATP synthase

Question 21

Structure of water?

Answer 21

H2O.

Question 22

Why is water a polar molecule?

Answer 22

unshared negative electrons on the oxygen atom give it a slight negative charge , this makes it polar because it has a slight partial negative and positive side on the other.

Question 23

Hydrogen bonding?

Answer 23

weak bonds between a slightly positively charged hydrogen atom and a slightly negatively charged atom in another molecule.

Question 24

properties of water?

Answer 24

1. important metabolite- hydrolysis and condensation reactions
2. good solvent, ions get totally surrounded by water molecules (dissolve)
3. high latent heat of vaporisation- water evaporates when hydrogen bonds holding water together are broken, this allows water molecules on the surface to escape as a gas- needs lots of energy to do this
4. can resist changes in temp- hydrogen bonds= high specific heat capacity
5. very cohesive- cause its polar- they stick together- helps water flow

Question 25

whats an ion?

Answer 25

atom/ group of atoms with an electrical charge

Question 26

ion with a positive charge is called?

Answer 26

cation

Question 27

ion with a negative charge is called an?

Answer 27

anion

Question 28

whats an inorganic ion?

Answer 28

ion which doesn’t contain carbon.