B1 Flashcards
What happens during the translation stage of protein synthesis?
Amino acids that match the triplet code on the mRNA are joined together in the correct order. This makes the protein coded for by the gene.
What happens during the transcription stage of protein synthesis?
- the two DNA strands unzip around the gene
- the DNA is used as a template to make the mRNA
- base pairing ensures it is complementary
What do enzymes do?
Control cell reactions.
What are enzymes also called?
Biological catalysts.
What happens if the substrate does not fit into the active site?
The reaction will not be catalysed.
What will happen to the enzyme when the pH is too high?
The shape of the active site will change and the enzyme will denature.
What is respiration?
The process of transferring energy from the breakdown of glucose.
What is the function of ATP?
Stores the energy needed for cell processes.
Is respiration a exothermic or endothermic reaction?
Exothermic. It transfer energy to the environment by heat.
What is the word equation for aerobic respiration?
glucose + oxygen -> carbon dioxide + water
What is the word equation for anaerobic respiration in animals?
glucose -> lactic acid
What is the word equation for anaerobic respiration in plants and fungi?
glucose -> ethanol + carbon dioxide
How much energy is transferred in aerobic respiration?
32 ATP
How much energy is transferred in anaerobic respiration?
2 ATP
Why is it advantageous for organisms to respire aerobically rather than anaerobically?
More ATP can be produced in aerobic respiration.
What are carbohydrate molecules made up of?
Simple Sugars
What can starch be broken down into?
Maltose and simple sugars.
How are carbohydrates managed in the body?
They are broken down (digested) by enzymes in the mouth and small intestine.
What are proteins made up of?
Amino acids.
How are proteins broken down in the body?
They are broken down by enzymes in the stomach and the small intestine.
What are Lipids made up of?
They are made up of fatty acids and glycerol.
How are lipids broken down?
They are broken down by enzymes in the small intestine.
Why is it so important for the body to be able to break down large complex molecules?
So energy can be transferred from their breakdown during respiration.
How can you test for sugars?
Benedict’s Reagent.
What color is Benedict’s Reagent?
Blue
What will happen if a test for sugar is positive?
A colored precipitate will form.
How can we observe the change in color of Benedict’s reagent?
The higher the concentration of reducing sugar, the further the color inclines to red.
How can you test for non-reducing sugars? (e.g Sucrose), and how do the results turn out?
- Add dilute hydrochloric acid to a new sample of the test solution and heat it in a water bath at 75 degrees Celsius.
- Add sodium hydrogen carbonate to neutralize it then carry the Benedict’s test
- colored = non-reducing sugars present
- not colored (stays blue) = no sugars present
How do you test the presence of starch? And how do the results turn out to be?
Iodine. Iodine is browny-orange and changes into a dark blue-black color if starch is present.
What is the Emulsion test used to test for?
Lipids.
What occurs if the results of the Emulsion test are positive?
They show up as a milky emulsion. The more lipid present, the noticeable the milky color will be.
How can you test for Proteins? What results can be observed?
The Biuret test. A few drops of sodium hydrochloride should be added to make the solution alkaline. Then add some copper (II) sulfate solution. If protein is present the solution will turn purple, blue if not present.
What is the word equation for photosynthesis?
Carbon dioxide + Water -> Glucose + Oxygen
How can you calculate the rate of photosynthesis?
light intensity = 1/ distance^2
