Membrane and Membrane Transport

If a saltwater fish is placed in fresh water, which of the following will occur?

• Cells of the fish will crenate

• Cells of the fish will burst

• Cells of the fish will be turgid

• Salt will diffuse from the fish to the water

Which is an example of facilitated diffusion?

• Diffusion of gases at the lungs

• Absorption of glucose at the small intestine

• Diffusion of potassium ions in axons

• Pumping of sodium ions out and potassium ions into the cell

Which is true about passive transport?

• molecules move from low to high concentration

• ATP is required

• molecules move from high to low concentration

• ATP is not required

Which process(es) require(s) energy?

• Osmosis

• Endocytosis

• Facilitated Diffusion

• Active Transport

Which component of the cell membrane is responsible for the fluidity of the membrane?

• Integral proteins

• Cholesterol

• Hydrocarbon tails

• Phosphate heads

What are some problems with the Davson-Danielli model?

• Assumed that proteins were on the outside of membrane

• Assumed that membranes were symmetrical

• Assumed that proteins were always in fixed positions

• Assumed that membranes were not fluid

What technologies allowed Singer and Nicholson to come up with the fluid mosaic model?

• Electron Microscope

• Freeze etching

• X-ray crystallography

• Fluorescent antibody tagging

What is involved in endocytosis?

• Invagination of the membrane

• Fusion of vesicle with membrane

• Movement of vesicle within cell

• Budding out of vesicles from golgi

Solution Y is ____________ to the plant cell. Plant cell is therefore ___________.

• hypertonic, plasmolysed

• hypotonic, plasmolysed

• hypertonic, turgid

• hypotonic, turgid

What controls the fluidity of the membrane?

• Glycoproteins

• Integral proteins

• Cholesterol

• Phospholipid bilayer