Key Concepts In Biology

Question 1

The ribosomes are the site of

Answer 1

Protein synthesis

Question 2

All cells need energy to function. Which cell organelle is responsible for releasing energy in the cell through aerobic respiration

Answer 2

Mitochondria

Question 3

What is the function of vacuoles

Answer 3

Storing water

Question 4

Why do very active cells have lots of mitochondria

Answer 4

As mitochondria release energy

Question 5

Which cell structure is found in plant and animals cells and controls what can come into or leave a cell?

Answer 5

Cell membrane

Question 6

What is the function of a cell wall

Answer 6

To protect and support the cell

Question 7

What is the function of a nucleus

Answer 7

To control cell activity

Question 8

What does the mitochondria do

Answer 8

This is where aerobic respiration occur

Question 9

What happens in the cytoplasm

Answer 9

A jelly like liquid where chemical reactions take place

Question 10

What do the chloroplasts do

Answer 10

They contain chlorophyll to absorb sunlight where photosynthesis occurs

Question 11

Prokaryotic

Answer 11

A single called organism with no nucleus

Question 12

Eukaryotic

Answer 12

An organism with have a nucleus

Question 13

Enzymes?

Answer 13

A biological catalyst that increases the rate of a reaction being chemically unchanged. By lowering the activation energy

Question 14

What is synthesis

Answer 14

This is when a New product is formed

Question 15

3 things that increase the rate of diffusion

Answer 15

The greater the difference in particle concentration
The greater the kinetic energy
The greater the temperature

Question 16

What do carbohydrates break down into

Answer 16

Simple sugars

Question 17

What enzyme breaks down carbohydrates

Answer 17

Amylase/ carbohydrase

Question 18

What do we call the model that explains enzyme specificity?

Answer 18

The lock and key model

Question 19

What is the optimum temperature for enzymes

Answer 19

37.5 degrees c

Question 20

What is the optimum pH for enzymes (except pepsin!)

Answer 20

Between 6-8 most optimum at 7

Question 21

What is the optimum ph for pepsin

Answer 21

Between 2-3

Question 22

What does protease break down

Answer 22

Protein

Question 23

How is the enzyme substrate complex formed

Answer 23

When substrate binds to the enzyme

Question 24

What happens on the active site of an enzyme

Answer 24

This is where the substrate binds

Question 25

How can the shape of an enzyme make it inactive

Answer 25

Small or blocked active site making it imposible for the substrate to fit perfectly making it impossible to form the enzyme substrate complex

Question 26

What are enzymes made of

Answer 26

Each enzyme is comprised of proteins made of these twisting and folding amino acids,

Question 27

How does temperature denature an enzyme

Answer 27

Extreme temperature breaks the forces between the amino acids that hold together a cell changing its shape

Question 28

How does ph denature an enzyme

Answer 28

Changing the pH will affect the charges on the amino acid molecules. Amino acids that attracted each other may no longer be. This changing the shape of the active site

Question 29

Describe how sperm cells are adapted to their function.

Answer 29

Acrosomes, which help to identify the target female reproductive cell and contain enzymes that break down the outer membrane of the egg, allowing the sperm to achieve fertilisation.

Question 30

Describe how ciliated epithelial cells are adapted to their function.

Answer 30

They have have cilia (which are hair-like structures) on the top surface of the cell. These cells move substances in one direction. These can be found along the lining of the airways. They move mucus.

Question 31

How are egg cells adapted

Answer 31

The cytoplasm contains a large volume of nutrients to help the embryo grow.
They are lined with cilia that helps move substances away.
They have a protective jelly coat that hardens after fertilization.
The egg cell membrane can fuse with the sperm cell membrane.

Question 32

The effect of substrate concentration on an enzyme

Answer 32

the rate of enzyme activity does not increase forever. This is because a point will be reached when the enzymes become saturated and no more substrates can fit at any one time

Question 33

Active transport

Answer 33

Active transport is the movement of dissolved molecules into or out of a cell through the cell membrane, from a region of lower concentration to a region of higher concentration. The particles move against the concentration gradient , using energy released during respiration .

Question 34

Effects of osmosis on a red blood cell

Answer 34

Red blood cells placed in a solution with a higher water concentration compared to their contents (eg pure water) will gain water by osmosis, swell up and burst. Water will diffuse from a higher water concentration outside the cell to a lower water concentration inside the cell.