Bio Quiz #2

Question 1

Cell Membrane

Answer 1

• all cells have cell membranes
• the cell membrane is which means it allows the passage of selectively permeable certain molecules
• the fluid mosaic model is used to describe the cell membrane

Question 2

What is the cell membrane made out of?

Answer 2

phospholipid bilayer : a double layer where the phosphate ends face out and are attracted to water, the lipids face in and repel water

protein channel : throughout the bilayer, may be attached outside, inside or pass all the way through, act as a gate or pump

cholesterol : found between phospholipids, helps hold the membrane together

Question 3

Particle Model of Matter

Answer 3

1. All matter is made of particles which vary in size and composition
2. The particles of matter are constantly moving and vibrating They move the least in solids and the most in gases. Adding or removing energy effects the movement of the particles

3 .The particles of matter are attracted to one another or are bonded together

4. Particles have spaces between them that are smallest in solids and greatest in gases (exception – ice). The spaces may be occupied by particles of another substance.

Question 4

2 types of Cell Transport

Answer 4

Passive Transport - No additional energy,
- Simple Diffusion
- Osmosis
- Facilitated Diffusion

Active Transport - Requires energy in the form ATP

Question 5

Simple Diffusion

Answer 5

• concentration gradient between 2 points
• molecules naturally move down the gradient, from high-con to low-con until concentration is equal in all areas
• the flow of nutrients/wastes in and out of the cell is regulated by the cell membrane (recall fluid mosaic model)
• it is caused by the collision of particles and is passive because no extra energy is required for it to occur nutrients/wastes cell membrane

Question 6

3 types of membrane

Answer 6

Permeable - allows
Semipermeable - some molecules
Impermeable - do not

Question 7

Diffusion rate is affected by…

Answer 7

size of molecules - small = fast
temperature - hot = fast
concentration - low = fast
medium - liquid/gas = fast

Question 8

Osmosis

Answer 8

• diffusion of water across a semipermeable membrane
• relies on concentration gradient