Hey this is the OCR BIOLOGY DEPTH mark scheme. From what im seeing everyone on twitter and in school said the timing of the paper was bad and it was hard.
Okay.
Question about non-competitive inhibitor?
- It binds to the allosteric site, the bonds of the tertiary structure change changing the active site therefore substrate is no longer complementary to the active site, therefore the enzyme is no longer functional.
Tachychardia was the grapth.
Cardiac Output was 5.44 TIMES 10 the power of 3
simpsons index of diversity was 0.73. (Final Answer is only 1 mark so dont worry).
Errors with DNA Purification was that she forgot to add the ethanol and grind the sample. Then describe what the protease or the detergent does.
Last Question was that species eveness was low because of the large jump.
Cardiac Cycle. Atrial Systole, atria wall contract, decreasing volume increasing pressure forcing blood into the Ventricles through the atrioventricular valves which open and is held by tendinous cords. Ventricular Systole, the walls of the ventricles contract decreasing volume increasing pressure, atrioventricular valves close to prevent backflow of blood into the atria, the increased pressure forces the semi-lunar valves to open forcing blood through the aorta and the pulmonary artery at a high pressure. Once all blood has been forced the ventrcles relax and the semi-lunar valves close. Then the atria and ventricles relax blood flows in ventrciles and atria.
Question about the electrical excitation of the heart?
SAN sends a wave of electrical excitation towards the AVN. AVN creates Delay. AVN sends wave of electrical excitation towards the bundle of his to the apex causing the ventricles to contract. Hence the QRS complex represents Ventricular Systole.
First Question:
Amine Group and carboxyl Group.
What bond does it represent and what reaction? It was a peptide bond in a condensation reaction.
Globular Fibrous Proteins- 3 marks if you say globular proteins are soluble and fibrous proteins are insoluble because the hydrophilic R group was on the outside of the globular protein making it soluble. Globular Proteins have metabolic roles such as pepsin which breaks down proteins. Fibrous Proteins have structural roles. 3 marks- Giving examples of fibrous and globular.
Design Experiment for Enzymes Question.
Get three test tubes. Place each sample into test tube. Use equal volume and concentration of the thing i cant remember. Place a tube which is inverted into a water bath which has no air bubbles. Add a tube inside place it in the test tubes and close with a bung. When ready add the thingy and close the bung and measure the water loss.
Three things to improve the experiment
- Wear gloves because her hand could have been contaminated with amino acids.
- Place a glass plate on top of the beaker in order to prevent air born particles from contaminating the chromatography paper and affecting the results.
- Draw a tiny dot on the middle of the line in order to know where to place the sample.
One aim of the cites- Prevents international trade of endangered species or Prevents international trade for commercial reasons.
Elephants population deaths inceased in central and west and include figures. Eastern Africa slighly increased but no as much as central and west and it was recent.
I remember one question where you did 10million-500 thousand divided by 10 million and you get 95 percent.
This is at least
45 marks of the paper.
Vote on this stawpool so we can estimate grade boundaries.
https://www.strawpoll.me/15830987/