Cell Membrane Transport

Question 1

What molecules give cell membrane their selectively permeable properties?

Answer 1

The middle parts of a cellular membrane ( phospholipid tails) is hydrophobic nonpolar impedes hydrophilic polar molecules from the crossing and also impedes ions including proteins channels.

Question 2

Give examples of molecules that move in to cells.. out of cells.

Answer 2

Small molecules and ions constantly move across cell membrane.

Into the cells: sugar, amino acids, other nutrients, oxygen,

Leaving cells: metabolic wastes, carbon dioxide, cellular products such as mucous, digestive enzymes, saliva, cerumen( ear wax).

Question 3

What types of molecules can easily pass through cell membrane

Answer 3

Very small polar molecules such as water, and ethanol can pass through the molecules easily.

Hydrophobic (nonpolar) molecules such as carbon dioxide and oxygen can easily cross the membrane

Question 4

What types molecules are blocked by the membrane

Answer 4

This impedes hydrophilic polar molecules from crossing and also impedes ions.

Question 5

What happened to the water in a cell due to osmosis if the cell is placed in a hypotonic solution?

Answer 5

Hypotonic- a solution with a lower concentration of solutes( higher concentration of free water molecules)

The water molecules move into the cell. Which will make the cell lysed( animal), turgid( plant cell)

Question 6

What happened to the water in a cell when it’s in a hypertonic

Answer 6

Hypertonic a solution with a higher concentration of solutes.
The cell loss water which will make the cell shriveled ( animal cell), shriveled plasmolyze ( plant cell)

Question 7

Isotonic solution

Answer 7

Refers to solution of equal solute concentration( equal concentration of water molecules)
There is no net movement of water into cell, and the cell is flaccid( limp)

Question 8

What is the difference between active transport and passive transport

Answer 8

Passive transport- no energy required

Active transport- energy required

Question 9

Active transport

Answer 9

Proteins pumps different direction
Exocytosis: using vesicles to export material from cells.
Endocytosis: pinocytosis( general gulping, drinking) and phagocytosis( specific reaches out eating.) white blood.

Question 10

Passive transport

Answer 10

Diffusion

1. Osmosis( water across a membrane)
2. Facilitated diffusion( proteins channels)
   - open proteins channel
   - gated channel.

Question 11

Concentration gradient

Answer 11

A region along which the density of a chemical substance increase or decrease.

Question 12

Hello

Answer 12

What’s up

Question 13

Dynamic equilibrium

Answer 13

Has to do with diffusion across a membrane

Ex. If there is water with a membrane dividing it and some dye is put on one side of the membrane( assuming the dye is able to pass through the membrane) the dye begins to randomly spread out moving across the membrane- back and forth.

Question 14

Crenation

Answer 14

A process results from osmosis in which red blood cells, in a hypertonic solution.
A cell in a hypertonic solution will be losing water. (They shrivel up) and plant become plasmolyzed- pull away from cell wall.

Question 15

Lysis

Answer 15

When a cell is in a hypotonic solution will be gaining water which cause lysis in animal cells (they burst) and plant turgid(firm)

Question 16

Plasmolysis

Answer 16

Contraction of the protoplast of a plant cell as a result of loss of water from the cell.

Question 17

Protein pumps

Answer 17

Are on the cell membrane. They are pumping something usually ions from areas of lower to higher concentration.

Question 18

Hydrophobic

Answer 18

Non polar molecules such as carbon dioxide and oxygen can easily cross the membrane

Tending to repel or fail to mix with water.

Question 19

Hydrophilic

Answer 19

“Water loving”Pertaining to polar or charge molecules (or parts of molecules) that are soluble in water.

Question 20

Diffusion

Answer 20

The tendency for molecules of any substance to randomly spread out in the available space.

Question 21

Osmosis

Answer 21

Diffusion of water across a membrane