Top answers

Give 3 differences in structure between DNA and mRNA

DNA contains the nucleotide base thymine whereas mRNA contains the nucleotide base uracil instead DNA is double stranded, mRNA is single stranded DNA contains the sugar subunit deoxyribose, mRNA contains the...
CB
Answered by Callum B. • Biology tutor
10766 Views

What does the DNA sequence being 'degenerate' mean?

Amino acids are coded for by specific codons. There are some instances where some particular amino acids can be coded for by more than one codon (codon being three nucleotides bonded together). This is known...
BN
Answered by Bibi N. • Biology tutor
12566 Views

Describe and explain the effects of pH, temperature, enzyme concentration and substrate concentration on enzyme activity

pH : All enzymes have an optimum pH value which is very specific. This is because hydrogen ions and hydroxide ions have very significant changes on the tertiary structure of an enzyme, which can cause substr...
EO
Answered by Eloise O. • Biology tutor
16793 Views

Putting bee honey on a cut kills bacteria. Honey contains a high concentration of sugar. Use your knowledge of water potential to suggest how putting honey on a cut kills bacteria.

Once honey is added to an infected cut, the osmotic gradient favours water moving from the bacterial cells to the honey. This is because the water potential is lower in the honey. As a result of the loss of ...
HM
Answered by Harry M. • Biology tutor
3987 Views

Why is it that an action potential only travels in one direction?

(draw/picture of nerve cell with its ion channels and after learning about the action potential trace and how it's derived) After each action potential, see on the trace there's a refractory period where the...
JL
Answered by Jasmine L. • Biology tutor
16003 Views