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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 'a...
KR
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state three differences between a plant cell and animal cell.

any three from: no cell wall in animal cells/ (cellulose) cell wall in plant cell centrioles present in animal cell, not in present in plant cell (permanent) vacuole in plant cell, lack of (permanent) vacuol...
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Answered by Rohan P. • Biology tutor
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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 int...
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Answered by Rohan P. • Biology tutor
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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 ca...
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Answered by Charlotte K. • Biology tutor
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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 the ...
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Answered by Harriet H. • Biology tutor
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