B1.2

Question 1

what is a long molecule of dna called

Answer 1

chromosome

Question 2

how many chromosomes are in each cell

Answer 2

46

Question 3

what are genes

Answer 3

short sections of dna, codes for characteristics

Question 4

what does the code each gene contains cause to be made

Answer 4

specific proteins, which determine the cells function

Question 5

what is dna made of

Answer 5

small units called nucleotides, made of a sugar, a phosphate group and a base

Question 6

what are the 4 bases

Answer 6

adenine, thymine, cytosine, guanine

Question 7

what makes up a dna nucelotide

Answer 7

phosphate, nitrogenous base, hydrogen bonds, and common sugar(deoxyribose)

Question 8

what does adenine bind with as there is no thymine in mRNA

Answer 8

uracil

Question 9

how are proteins made

Answer 9

translation

Question 10

what are proteins made from

Answer 10

amino acids; different amino acids join together to form different proteins.

Question 11

what is transcription

Answer 11

the dna around a gene ‘unzips’. complementary bases attach to one of the dna strands. when complete, the mRNA detaches, and DNA zips back up. the mRNA then travels to ribosomes in the cytoplasm, where proteins are made.

Question 12

what is translation

Answer 12

the mRNA attaches to a ribosome. the ribosome reads the nucleotides on the mRNA in groups of 3(codons). the ribosome continues to read the triplet code, adding more amino acids. the amino acids join together in a chain. this is a protein. each protein has a specific shape for function and many types are produced ( eg enzymes or hormones)

Question 13

what are the conditions where enzymes work best called

Answer 13

optimum conditions

Question 13

what does the rate of an enzyme- catalysed reaction depend on

Answer 13

temperature, pH, concentrations, conditions where the enzyme works the best are the optimum conditions.

Question 14

what happens with temperature and ph when it increases ( rate of reaction)

Answer 14

the higher the temperature, the faster the reaction but if it gets too high, the amino acid chains in the protein start to unravel, changing the shape of the active site, causing the enzyme to denature(irreversible) and its also the same for ph

Question 15

what happens with substrate concentration when it increases ( rate of reaction)

Answer 15

the higher the substrate concentration, the faster the rate of reaction until all the enzymes are bound to substrate molecules (reaches its maximum)

Question 16

what happens with enzyme concentration when it increases (rate of reaction)

Answer 16

the higher the enzyme concentration, the faster the rate of reaction but if no new substrate molecules are added, the reaction will stop.

Question 17

what is the definition of a biological catalyst

Answer 17

they speed up a reaction without being used up themselves. once a reaction is finished, they can be used to catalyse the same type of reaction again.

Question 18

what are enzymes

Answer 18

enzymes are made of protein, and they are biological catalysts

Question 19

what do enzymes do

Answer 19

enzymes build larger molecules from small ones, (e.g: protein synthesis) or other way round(e.g digestion)

Question 20

what are enzymes made of

Answer 20

long chains of amino acids

Question 21

how do enzymes form a specific shape

Answer 21

they are folded to form a specific shape where molecules or other substrates bind to the enzymes by active site.