cell fluids/membranes and transport

Question 1

homeostasis

Answer 1

body systems which work together to make sure that the cellular environment is kept constant

to maintain a constant and stable cellular environment

Question 2

plasma membranes

Answer 2

all the membranes that surround and are contained within the cell

Question 3

2 types of body fluids

Answer 3

intracellular (protoplasm): contained within cell membrane

extracellular: outside of the cell membrane

Question 4

Types of Intracellular fluids

Answer 4

Cytoplasm

Nucleoplasm

Question 5

Functions of cell membrane

Answer 5

1. surrounds and protects: from extracellular fluids (which have a varying composition to intracellular fluids)
2. sensitive to changes: the first area of the cell affected by changes in the external environment
3. regulates the passage of materials in and out of the cell: all materials must pass through the cell membrane before introduced in the cell
4. supports: the membrane is connected to the cytoskeleton which supports the cell. Also provides support to the whole tissue as cell is connected to other cells.

Question 6

types of extracellular fluids

Answer 6

intercellular fluid: between cells

plasma/lymph fluid

Question 7

Function of proteins in the cell membrane

Answer 7

carry out functions of the cell membrane

Question 8

Types of proteins (cell membrane)

Answer 8

Integral proteins: channel and carrier

peripheral proteins

Question 9

What is the phospholipid bilayer and what is it made of

Answer 9

A double layer of phospholipids. The hydrophilic heads facing outwards while the hydrophobic tails are facing inwards. The phospholipids consist of a phosphate, glycerol and 2 fatty acid tails.

Question 10

Why is the cellular membrane differentially permeable

Answer 10

allows the passage of some ions and molecules but restricts the entrance of others

Question 11

what is the difference between passive processes and active processes

Answer 11

passive processes: does not require the usage of energy and can occur in dead cells
active processes: does require the usage of energy and can therefore only occur in living organisms

Question 12

what is simple diffusion

Answer 12

high concentration -> low concentration (along concentration gradient)
small molecules diffuse across membranes gaps (co2,o2)
the bigger the concentration gradient, the faster the rate of diffusion

Question 13

osmosis

Answer 13

diffusion of water across a differentially permeable membranes from areas of high concentration to areas of low concentration (along C.G)

in solution, water moves from areas of low concentration of solute to high concentration of solute.

Question 13

osmotic pressure

Answer 13

large concentration gradient - large osmotic pressure

the force that tends to push water from areas of high concentration to low, or pull water from areas of low concentration to high concentration.

Question 13

facilitated diffusion

Answer 13

carrier proteins (not channel)
large molecules such as glucose and amino acids
carrier protein changes shape and opens other end for the passage of molecules
once saturated, rate of diffusion cannot be increased

Question 14

active transport

Answer 14

low concentration - high concentration (against concentration gradient)
active - energy needed
small/large molecules - sodium, potassium, glucose

does not require the concentration gradient to transport molecules - energy is applied it can be done

Question 14

vesicular transport

Answer 14

materials in and out of cell through a vesicle which is a membrane formed when vesicle pinches of from the cell membrane.

endocytosis: take into the cell
- phagocytosis: engulf microorganisms (solid)
- pinocytosis: absorb nutrients from food in villi of digestive tract (liquid)

Exocytosis: out of cell, expel vesicle

• waste products, co2
• saliva, breast milk