progress task 1

Question 1

which of the following is a characteristic of organelles?

A: they are only found in eukaryotic cells
B: they are only found in prokaryotic cells
C: they are sub-cellular structures
D: they are all membrane bound in a multicellular organism

Answer 1

C: they are sub-cellular structures

Question 2

insulin polypeptides are made during the process of translation. describe translation [3].

Answer 2

translation. this means that
- the ribosome reads the mRNA code for insulin. [1]
- tRNA brings the correct and specific amino acid to the ribosome. [1]
- tRNA anticodons are complementary and specific to mRNA codons.
- amino acids are joined together by a peptide bond in a condensation polymerisation reaction and an insulin polypeptide is formed. [1]

Question 3

all cells, despite their cellular structure, remain relatively small. explain how the surface area to volume ratio influences cells to remain small throughout evolution [2].

Answer 3

because a 𝘀𝗺𝗮𝗹𝗹𝗲𝗿 𝗰𝗲𝗹𝗹 has a 𝗹𝗮𝗿𝗴𝗲𝗿 𝘀𝘂𝗿𝗳𝗮𝗰𝗲 𝗮𝗿𝗲𝗮 𝘁𝗼 𝘃𝗼𝗹𝘂𝗺𝗲 𝗿𝗮𝘁𝗶𝗼,
then it makes it easier to 𝗺𝗮𝘅𝗶𝗺𝗶𝘀𝗲 𝘁𝗵𝗲 𝗲𝘅𝗰𝗵𝗮𝗻𝗴𝗲 𝗼𝗳 𝗻𝘂𝘁𝗿𝗶𝗲𝗻𝘁𝘀 𝗮𝗻𝗱 𝘄𝗮𝘀𝘁𝗲,
therefore cells are evolved to stay small.

Question 4

draw and label a diagram to show how a chemical reaction takes place to join two amino acids together. [3]

Answer 4

[1] - labelling condensation polymerisation next to arrow
[1] - drawing correct dipeptide
[1] - label H2O as a product

Question 5

a student was investigating the optimum pH for lipase. assume the student has access to 5 different pH solutions. outline a controlled experiment to test this [5].

Answer 5

[1] - there will be two groups: an experimental group and a control group. in the experiment group, the pH will be changed by using 5 different pH solutions (e.g. 1, 3, 5, 7, 9).
[1] - add 5cm3 of lipase to a test tube. add 10cm3 of the pH 1 solution. add 10cm3 of sodium carbonate.
[1] - the rate of reaction of lipase will be measured by the time taken for the solution to become neutral (seconds) using a pH probe. all other variables will be kept the same, such as concentration of lipase and temperature.
[1] - repeat the above for the other pH solutions (3, 5, 7, 9). for the control group, repeat the above but without lipase. repeat the experiment many times.
[1] - if ___ is the best pH for lipase, then that will turn neutral more quickly.

Question 6

describe why the genetic code can be referred to as universal. [1]

Answer 6

this means that each codon is translated into the same amino acid in all living things.