Structure and Role of Cell Membranes (OCR A-Level Biology A): Quizzes
📚Quizzes
Practise the questions
10 questions from this quiz
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Practise the questions
10 questions from this quiz
What term describes membranes that allow some substances through whilst blocking others?
What term describes membranes that allow some substances through whilst blocking others?
Selectively permeable
In the fluid mosaic model, what does 'fluid' refer to?
In the fluid mosaic model, what does 'fluid' refer to?
Lateral movement of phospholipids & proteins
What is the hydrophilic part of a phospholipid molecule?
What is the hydrophilic part of a phospholipid molecule?
Polar head with phosphate group
Why do phospholipid heads face outward in the bilayer?
Why do phospholipid heads face outward in the bilayer?
Heads are hydrophilic, attracted to water
How do channel proteins differ from carrier proteins?
How do channel proteins differ from carrier proteins?
Channels form pores; carriers change shape
What role do glycoproteins play in cell signalling?
What role do glycoproteins play in cell signalling?
Act as receptor molecules for hormones
How does cholesterol regulate membrane fluidity?
How does cholesterol regulate membrane fluidity?
Prevents excess fluidity & crystallization
At what temperature do membrane proteins begin to denature?
At what temperature do membrane proteins begin to denature?
Approximately 40°C
Why do organic solvents increase membrane permeability?
Why do organic solvents increase membrane permeability?
They dissolve lipids in the membrane
What causes the sharp absorbance increase in beetroot at 40-60°C?
What causes the sharp absorbance increase in beetroot at 40-60°C?
Protein denaturation breaking down membrane