Key Concepts in Biology

Question 1

What type of cell is an Animal Cell?

Answer 1

Eukaryotic

Question 2

What type of cell is a Plant Cell?

Answer 2

Eukaryotic

Question 3

Which sub-cellular structures are in Animal Cells?

Answer 3

Nucleus, Cell Membrane, Cell Wall, Chloroplasts, Mitochondria and Ribosomes

Question 4

Which sub-cellular structures are in Plant Cells?

Answer 4

Nucleus, Cell Membrane, Cell Wall, Chloroplasts, Mitochondria, Vacuole and Ribosomes

Question 5

What is the function of the Nucleus?

Answer 5

Stores the cell’s DNA

Question 6

What is the function of the Cell Membrane?

Answer 6

Controls what enters and leaves the cell

Question 7

What does the Cell Wall do?

Answer 7

Provides structure and limits the risks of Osmosis

Question 8

What does the Chloroplast do?

Answer 8

Site of Photosynthesis

Question 9

What is the function of the Mitochondria?

Answer 9

Aerobic Respiration

Question 10

What is the function of the Vacuole?

Answer 10

Storage of Substances

Question 11

What do Ribosomes do?

Answer 11

Protein Synthesis

Question 12

What type of cell is Bacteria?

Answer 12

Prokaryotic

Question 13

How are Sperm Cells adapted to their function?

Answer 13

Acrosome, Haploid Nucleus, Mitochondria and Tail

Question 14

How are Egg Cells adapted to their function?

Answer 14

Nutrients in the Cytoplasm, Haploid Nucleus and changes in the Cell Membrane after fertilisation

Question 15

What is the function of an Acrosome?

Answer 15

Helps the sperm penetrate the egg’s coat

Question 16

Why does the Cell Membrane of an Egg Cell change after fertilisation?

Answer 16

So no more sperm can enter the egg cell

Question 17

What are Ciliated Epithelium cells?

Answer 17

Ciliated Epithelium is a thin tissue that helps move particles out of the body

Question 18

How have improved technology in Microscopes increased our understanding of Sub-Cellular structures?

Answer 18

Improved magnification has allowed us to see Sub-Cellular structures in more detail and closer.

Question 19

Which is more powerful, an Electron microscope or a Light Microscope?

Answer 19

Electron

Question 20

Which measurement would this be - 10^-3?

Answer 20

Milli

Question 21

Which measurement would this be - 10^-6?

Answer 21

Micro

Question 22

Which measurement would this be - 10^-9?

Answer 22

Nano

Question 23

Which measurement would this be - 10^-12?

Answer 23

Pico

Question 24

What is the Active Site in Enzymes?

Answer 24

The part where the substrate binds and where the catalytic action happens

Question 25

What are 3 Factors Affecting Enzyme Activity?

Answer 25

Temperature, pH and Concentration

Question 26

What is a denatured Enzyme?

Answer 26

An Enzyme that has lost its structure, can no longer function and has lost any catalytic advantage

Question 27

How does Temperature affect Enzyme Activity?

Answer 27

Every enzyme and active site has an optimum temperature at which it’s reactions are at its fastest. For humans that temperature at 37 degrees C

Question 28

How does pH affect Enzyme Activity?

Answer 28

Enzyme activity is at its maximum value at the optimum pH. If the pH increases above this or decreases below this, the enzyme activity decreases and the enzymes become denatured.

Question 29

How does Concentration affect enzyme activity?

Answer 29

If there are more enzymes, more enzyme-substrate complexes form. This increases activity until a certain point. Eventually there are not enough substrate molecules to react with enzymes.

Question 30

How do you calculate the rate of Enzyme Activity?

Answer 30

Rate = Change/Time

Question 31

What are Enzymes made of?

Answer 31

Large proteins (amino acids)

Question 32

What is the Lock and Key model?

Answer 32

The substrate needs to bind perfectly with the the active site, like a key needs to fit perfectly with the door.

Question 33

What is the Induced Fit model?

Answer 33

The active site can change slightly to fit the substrate

Question 34

Which model is more realistic?

Answer 34

Induced Fit Model

Question 35

What is the Benedict’s test for?

Answer 35

Sugars

Question 36

What is the Iodine test for?

Answer 36

Starch

Question 37

What is the Biuret test for?

Answer 37

Proteins

Question 38

What is the Emulsion test for?

Answer 38

Lipids

Question 39

How does the Benedict’s test work?

Answer 39

- It tests for reducing sugars - Transfer **5cm^3** of a food sample to a test tube - Get a water bath and heat it to **75 degrees C** - Add **10 drops** of the Benedict’s solution to the test tube - Place the test tube in the water bath for **5 minutes** - If no reducing sugars are present, the solution will **stay blue** - If reducing sugars are present, the solution will go **Green, Yellow or Red**

Question 40

How does the Iodine test work?

Answer 40

- Put **5cm^3** of a food sample in a test tube - Add a few drops of Iodine solution - This will turn the solution a **brown-orange** colour - Shake the test tube gently and if there is starch present, the solution will go **blue-black**

Question 41

How does the Biuret test work?

Answer 41

- Add **2cm^3** of a food sample to a test tube - Add another **2cm^3** of Biuret’s solution (Potassium Hydroxide and Copper Sulphate) to the test tube - This will turn the solution **blue** - Shake the test tube gently - If there are proteins present, the solution will turn **pink-purple**

Question 42

How does the Emulsion test work?

Answer 42

- Put your food sample into a test tube - Add **2cm^3** of Ethanol - Shake the test tube vigorously - Add **2cm^3** of Distilled Water - If it goes a **cloudy-white** colour, lipids are present