2A Cell membrane and transport

Describe the structure of the cell membrane
[type 1/2 for answers]

• - Two monolayers form a bilayer

• - Fatty acid chains are (polar/non-polar) so they point (towards/away from) water

• - Phosphate groups are (polar/non-polar) so they form hydrogen bonds and point (towards/away from) water

All are factors affecting fluidity of cell membrane except

• Percentage of unsaturated fat

• Cholesterol conc

• Glycoproteins

• Fatty acid tail length

• Lipoproteins

• [type 1/2 for answers]

• - Phospholipids and proteins can move within their monolayer: (fluid/mosaic)

• - Proteins and glycoproteins randomly inserted in plasma membrane: (fluid/mosaic)

All are properties of cell membrane except

• Controls movement of substances into and out of the cell

• Allow cell recognition by having cell surface antigens to mark cell for destruction

• Receptors for cell signalling molecules like hormones and neurotransmitters

• Glycoproteins and glycolipids form hydrogen bonds with water for stability

Select all the types of channel proteins

• Aquaporins

• Voltage gated

• Mechanically gated

• Na+/K+ Pump

• Proton pump

[type 1/2 for answers]

At higher temperature, fluidity (increases/decreases), so cholesterol keeps fatty acid chains (apart/close together) to stabilise membrane fluidity

Functions of Glycolipids include all except

• Form hydrogen bonds with water to stabilise the membrane

• Antigen

• Receptor

• Enzyme

Answer explanation

Glycolipids can’t be enzymes as they’re not proteins.

Role of Glycolipids (HAR)

• - hydrogen bonds with water

• - antigen

• - receptor

All are the results of high temperature on cell membrane except

• Loss of secondary and tertiary structure of protein

• Breakage of ionic, hydrogen, hydrophobic interactions, peptide and disulphide bonds

• Unable to transport polar molecules

• Unable to receive cell signals

Identify D
(Choose all the possible names)

• Integral Protein

• Peripheral protein

• Glycoprotein

• Extrinsic protein

Identify F

• Peripheral protein

• Glycoprotein

• Glycolipid

• Integral protein