Proteins in the cell membrane Flashcards Preview

Biology A-level > Proteins in the cell membrane > Flashcards

Flashcards in Proteins in the cell membrane Deck (18)
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1
Q

Two groups of proteins:

A

integral proteins (intrinsic) and peripheral proteins (extrinsic)

2
Q

Integral proteins can be found in…

A

the inner, outer layer or spanning the whole membrane. (transmembrane proteins)

3
Q

Some of the integral proteins are…

A

fixed.

4
Q

Peripheral proteins are found…

A

on the inner or outer surface of the membrane.

5
Q

Transport proteins form…

A

hydrophilic channels or passageways for ions and polar molecules to pass through the membrane.

6
Q

Types of transport proteins:

A
  • channel proteins

- carrier proteins

7
Q

Glycoprotein or glycolipid has…

A

short branching chain of carbs attached to the protein or lipid.

8
Q

Carb chains are attached to…

A

the side of a molecule which faces outside.

9
Q

Glycoproteins and glycolipids functions:

A
  • the chains project into water fluids where they form hydrogen bonds, which stabilises the membrane
  • can form a sugary coating =glycocalyx
  • antigens
10
Q

Channel proteins are water-

A

filled pores.

11
Q

Channel proteins allow charged…

A

substances to diffuse.

12
Q

Most of the channel proteins are

A

gated. Part of the protein molecule on the inside surface of the membrane can move to close or open the pore.

13
Q

Some of the channels occur in…

A

a single protein, other can be formed by several proteins.

14
Q

Channel proteins have fixed…

A

shapes.

15
Q

Carrier proteins can flip…

A

between two shapes.

16
Q

As a result of a change in the shape of carrier protein…

A

the binding site is opened to one side of the membrane, then the other.

17
Q

Factors affecting the rate of facilitated diffusion:

A
  • the number of channel and carrier proteins

- how many channel proteins are opened

18
Q

Cystic fibrosis is caused by…

A

a defect in channel protein that should be present in certain cells. This protein normally allows Cl- ions to move out of the cell.