Cell Membrane and Transport

Question 1

What is the cell membrane made up of?

Answer 1

Phospholipids. 2 hydrocarbon tails that are hydrophobic and one phosphate head that is hydrophilic. Form a bilayer.

Question 2

What are membrane proteins?

Answer 2

Other parts of the cell membrane. Integral proteins are embedded in the membrane and peripheral proteins are on the surface of the membrane.

Question 3

What are glycoproteins?

Answer 3

Carbohydrates attached to proteins. They act as cell markers to determine cell type. Act as receptor proteins that recognize and bind to substances outside the cell.

Question 4

What are glycolipids?

Answer 4

Carbohydrates attached to lipids. Contribute to the stability of the membrane.

Question 5

What are the other types of proteins?

Answer 5

Enzymes and transport proteins.

Question 6

Cell membranes can be :

Answer 6

1. Permeable/porous
2. Impermeable
3. Semi-permeable

Question 7

What is homeostasis?

Answer 7

Maintaining a stable cell environment in the cells interior.

Question 8

What direction is concentration movement?

Answer 8

High to low. Substances move from where it is more concentrated to less concentration/down its concentration gradient.

Question 9

What are the 2 types of transport?

Answer 9

1. Passive: no energy required, just the movement from high to low concentration.
2. Active: requires energy, and moves substances against the concentration gradient.

Question 10

Osmosis

Answer 10

Passive transport. 3 types of osmatic environments:
1. Hypotonic Environment, high H2o and low solutes in ECF reverse for ICF. Water moves into the cell.
2. Hypertonic Environment, low H2o and high solutes in ECF reverse ICF. Water moves out of the cell.
3. Isotonic Environment, both ECF and ICF are equal.

Question 11

Diffusion

Answer 11

Passive transport. 2 types:
1. SImple Diffusion, dependent on particle size, polarity and temperature.
2. Facilitated Diffusion, which uses transport proteins

Question 12

Transport Proteins

Answer 12

1. Channel Proteins: ECF and ICF can mix. Faster transport, not selective. Transports water and small ions.
2. Carrier Proteins: ECF and ICF don’t mix. SLower transport, selective. Transports glucose and amino acids.

Question 13

Sodium Potassium Pump

Answer 13

Runs on ATP energy is a form of Active Transport. uses ATP to transport low concentrations of 3 sodium from the ICF to the ECF, and transports low concentrations of 2 potassium to ICF.

Question 14

Endocytosis

Answer 14

The cell membrane folds inward, enclosing small particles from ECF.

Question 15

Pinocytosis

Answer 15

“Drinking”. Intakes fluid from the ECF with dissolved particles.

Question 16

Phagocytosis

Answer 16

“Eating”. Intakes large solid particles from the ECF. Occurs only in specialized cells.

Question 17

Exocytosis

Answer 17

Vesicle from ICF moves to the surface, and it fuses with the membrane, restoring the membrane used in endocytosis. The content of the vesicle is released into the EDF.

Question 18

Cell Sizes (smallest to largest)

Answer 18

1. Water
2. Glucose
3. Starch
4. Membrane pores