Topic 1 - Key Concepts

Question 1

Two differences between an animal cell and a plant cell

Answer 1

An animal cell doesn’t have:

• chloroplasts
• cell wall

Question 2

Name four things that an animal cell and a plant cell have in common

Answer 2

They both have:

• cell membranes
• nucleus
• mitochondria
• cytoplasm

Question 3

What are three extra things that a plant cell has, that an animal cell doesn’t have?

Answer 3

A plant cell has:

• a vacuole
• chloroplasts
• a rigid cell wall

Question 4

What is a bacterial cell made up of?

Answer 4

• cell wall
• cell membrane
• cytoplasm
• ribosomes
• flagella
• DNA

Question 5

What’s the difference between eukaryotes (animal and plant cells) and prokaryotes (bacterial cells)?

Answer 5

Eukaryotes have a membrane bound nucleus whereas prokaryotes don’t

Question 6

What is the role of the nucleus?

Answer 6

The nucleus controls what the cell does

Question 7

What is the role of the cytoplasm?

Answer 7

The cytoplasm is where all the chemical reactions take place

Question 8

What is the role of the mitochondria?

Answer 8

The mitochondria turns glucose and oxygen into energy

Question 9

What is the role of the cell membrane?

Answer 9

The cell membrane holds the cell together and controls why goes in and out

Question 10

What is the role of chloroplasts?

Answer 10

Chloroplasts contain green chlorophyll for photosynthesis

Question 11

What is the role of the cell wall?

Answer 11

The cell wall gives support to the cell

Question 12

What is the role of the vacuole?

Answer 12

The vacuole contains cell sap which is a weak solution of sugar and salts

Question 13

What is the role of ribosomes?

Answer 13

Ribosomes build proteins

Question 14

What is the role of the flagella?

Answer 14

The flagella give bacteria ability to move about activity

Question 15

What does the DNA hold?

Answer 15

Genes

Question 16

How do you calculate the magnification?

Answer 16

Magnification = measured size /

actual size

Question 17

Magnification conversions

Answer 17

Millimeter - 10 to the -3
Micrometer - 10 to the -6
Nanometer - 10 to the -9
Picometer - 10 to the -12

Question 18

What are enzymes?

Answer 18

They are a particular group of proteins that speed up a chemical reaction in the body. Known as a biological catalyst.

Question 19

Some enzymes are used to break down larger substances into smaller ones e.g…

Answer 19

Digestion

Question 20

Other enzymes are used to help smaller chemicals join together to make larger ones e.g…

Answer 20

Synthesis

Question 21

What are the molecules that enzymes work on called?

Answer 21

Substrate molecules

Question 22

When do enzymes work best?

Answer 22

At optimum temperature

At optimum pH

Question 23

What is the active site?

Answer 23

The active site is the part of an enzyme that has a specific shape so that only the right substrate can fit into it

Question 24

What changes the shape of an active site and how?

Answer 24

Changing temperature
Changing pH

They both break the bonds within the enzyme so that the active site changes shape and the enzyme is denatured.

Question 25

Name 3 enzymes and where they are found

Answer 25

Protease - found in stomach, small intestines and pancreas
Lipase - found in pancreas and small intestines
Amylase - small intestines, pancreas and salivary glands

Question 26

What do protease, lipase and amylase do?

Answer 26

Protease turns proteins into amino acids
Lipase turns lipids into fatty acids and glycerol
Amylase turns starch into sugars

Question 27

What is diffusion?

Answer 27

Diffusion is when something travels along the concentration gradient, from a high concentration to a low concentration

Question 28

What is osmosis?

Answer 28

Osmosis is when water diffuses from a concentrated area to a less concentrated area through a partially permeable membrane

Question 29

What is active transport?

Answer 29

Active transport is when substances move against the concentration gradient