Top answers

Biology
A Level

How can I improve my exam technique?

A common problem amongst Biology students is the difficulty in knowing the content well, but not being able to translate this knowledge into marks when it comes to the exam. Your exam technique is vitally...

LD
Answered by Lucy D. Biology tutor
6803 Views

Describe how mRNA is produced within a cell

DNA is unwound by DNA helicase. This exposes the two strands of DNA, through the breaking of hydrogen bonds. This allows for complementary RNA nucleotides to join to one of the two strands - i.e. they are...

KR
2655 Views

how is a proton gradient set up and maintained across the inner mitochondrial membrane?

H+ ions and electrons released from NADH and FADH2,on to the inner mitochondrial membrane. electrons enter electron transport chain, and energy released from transfer of electrons is used to pump H+ ions ...

RP
Answered by Rohan P. Biology tutor
20990 Views

How does the sliding filament theory work?

A nerve impulse in the sarcoplasmic reticulum causes calcium ions to move out of it into the muscle cells where it binds to tropmyosin/troponin causing it to move and reveal the actin filament. The myosin...

CK
Answered by Charlotte K. Biology tutor
7695 Views

What is meant by the "fluid-mosaic" model of cell membrane structure?

The cell membrane consists of a double layer of phospholipids, with proteins floating in it. Phospholipids are a type of molecule with a phosphate head, and fatty tails, which form a double layer around t...

HH
Answered by Harriet H. Biology tutor
26761 Views

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