Unit 1 - Wellness & Homeostasis

Question 1

What is homeostasis

Answer 1

Maintaining a stable internal environment.

Question 2

What is a cell

Answer 2

the basic unit of the structure and function of living things.

Question 3

What are the three main parts of cell theory

Answer 3

1. all organisms are made up of one or more cells
2. all the life functions of an organism occur within cells
3. all cells come from preexisting cells.

Question 4

Describe the role of the cell membrane

Answer 4

It protects and supports the cell and also controls everything that enters and leaves the cell

Question 5

What is Semipermeability

Answer 5

the ability to allow only certain molecules in or out of the cell

Question 6

Describe the composition of the cell membrane.

Answer 6

is composed mainly of phospholipids, which consist of fatty acids and alcohol. The phospholipids in the cell membrane are arranged in two layers, called a phospholipid bilayer.

Question 7

Discuss the Fluid Mosaic Model.

Answer 7

proteins are embedded in the phospholipid bilayer forming a mosaic pattern

Question 8

Explain how diffusion and facilitated diffusion differ.

Answer 8

Facilitated diffusion makes use of transport proteins

Question 9

What is a transport protein? Give 2 examples.

Answer 9

transport protein completely spans the membrane, and allows certain molecules or ions to diffuse across the membrane. Channel proteins and carrier proteins

Question 10

Explain how carrier proteins function?

Answer 10

“carry” the ion or molecule across the membrane by changing shape after the binding of the ion or molecule.

Question 11

What is osmosis? What type of transport is it?

Answer 11

Diffusion of water → Passive transport

Question 12

How does osmosis differ from diffusion?

Answer 12

It is a specific type of diffusion (water)

Question 13

What happens to red blood cells when placed in a hypotonic solution?

Answer 13

They swell and may burst

Question 14

What will happen to a salt water fish if placed in freshwater?

Answer 14

They will lose water and shrink or shrivel

Question 15

What is diffusion?

Answer 15

When molecules move from a area of high concentration to low concentration

Question 16

What is a concentration gradient?

Answer 16

difference in the concentrations of the molecules in the two areas

Question 17

What is meant by passive transport?

Answer 17

a way that small molecules or ions move across the cell membrane without input of energy by the cell

Question 18

What is active transport?

Answer 18

is the energy-requiring process of pumping molecules and ions across membranes “uphill” - against a concentration gradient.

Question 19

Explain how cell transport helps an organism maintain homeostasis.

Answer 19

It helps to ensure that the cell has the right molecules it needs and wastes can be expelled

Question 20

What is the difference between endocytosis and exocytosis?

Answer 20

Endo- moving substances in
Exo- moving substances out

Question 21

Why is pinocytosis a form of endocytosis?

Answer 21

Because it’s bringing liquid molecules into the cell

Question 22

Compare autotrophs to heterotrophs, and describe the relationship between these two groups of organisms.

Answer 22

Autotrophs store chemical energy in carbohydrate food molecules they build themselves.

Heterotrophs cannot make their own food, so they must eat or absorb it.

Heterotrophs consume autotrophs or other heterotrophs that have eaten autotrophs.

Question 23

The fact that all organisms use similar energy-carrying molecules shows one aspect of the grand “Unity of Life.” Name two universal energy-carrying molecules, and explain why most organisms need both carriers rather than just one.

Answer 23

Glucose → can store a lot of energy; has just the right amount of energy for transport and uptake of cells

ATP → has just the right amount of energy for cells to use to do work

Question 24

A single cell uses about 10 million ATP molecules per second. Explain how cells use the energy and recycle the materials in ATP.

Answer 24

An ATP molecule,, is like a rechargeable battery: its energy can be used by the cell when it breaks apart into ADP (adenosine diphosphate) and phosphate, and then the “worn-out battery” ADP can be recharged using new energy to attach a new phosphate and rebuild ATP. The materials are recyclable, but recall that energy is not!

Question 25

ATP and glucose are both molecules that organisms use for energy. They are like the tank of a tanker truck that delivers gas to a gas station and the gas tank that holds the fuel for a car. Which molecule is like the tank of the delivery truck, and which is like the gas tank of the car? Explain your answer.

Answer 25

Glucose is like the tank of the delivery truck because it contains a lot more energy than ATP and this is how energy is transported throughout the body

ATP is like the gas tank of the car because this is the energy molecules that cells use to do work.

Question 26

Define cellular respiration.

Answer 26

This process releases the energy in glucose to make ATP