Top answers

Biology
A Level

What are proteins?

Proteins are polymers made of amino acids. Proteins are essential molecules. Among many other roles, they can catalyse numerous reactions within the body (these proteins are known as enzymes), they allow ...

SL
Answered by Suzi L. Biology tutor
3505 Views

How does the release of calcium ions regulate muscle contraction?

Tropomyosin is a protein that covers the actin binding site. This prevents a cross-bridge forming between the myosin and actin filaments whilst the muscle is at rest. Calcium ions bind to troponin molecul...

ET
Answered by Emily T. Biology tutor
4706 Views

How does oxidative phosphorylation work in respiration

Reduced NAD/FAD from previous stages of respiration (glycolysis, link reaction, Krebs cycle) relocate from the mitochondrial matrix to the inner mitochondrial membrane. At this point they are oxidised, lo...

FM
Answered by Fionn M. Biology tutor
3725 Views

What is the Hardy-Weinberg equilibrium and when is it used? With an example

The Hardy-Weinberg equilibrium is used to work out dominant and recessive allele ratios in a population regarding one gene. Dominant alleles are those which when at all present in the genotype develops a ...

EB
Answered by Ellie B. Biology tutor
9715 Views

Explain how water is re-absorbed in the kidney

It would be helpful for you to have a diagram of a kidney nephron in front of you as you read this explanation. The body has a clever mechanism to conserve water levels, it creates a strong salt concentra...

CD
Answered by Charlotte D. Biology tutor
31322 Views

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