From Big To Small - GCSE spec

Question 1

What is a cell?

Answer 1

The smallest possible unit of life.

Question 2

What are organelles? What is there function?

Answer 2

Small structures within the cytoplasm of the cell. They carry out vital processes that the cell needs to survive.

Question 3

What do animal cells consist of?

Answer 3

Cell Membrane, Cytoplasm, Ribosomes, Nucleus, Mitochondria.

Question 4

What do plant cells consist of?

Answer 4

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

Question 5

What is the function of the nucleus?

Answer 5

Controls the activity of the cell and holds the Chromosomes (Strands of DNA( Which carry genes)) for the cell

Question 6

What is the cell membrane?

Answer 6

The cell membrane is the boundary between the cytoplasm and the surroundings of the cell. Controls what goes in and out of the cell.

Question 7

What is the Cytoplasm?

Answer 7

Jelly like liquid where chemical reactions occur.

Question 8

What is Mitochondria?

Answer 8

The site of aerobic respiration.

Question 9

What are Ribosomes?

Answer 9

Synthesise proteins from amino acids.

Question 10

What are chloroplasts?

Answer 10

Absorbs light’s energy and is the site of Photosynthesis.

Question 11

What is the Cell wall?

Answer 11

Cell wall is made of cellulose and this makes the cell hold its shape (Keep the plant upright)

Question 12

What is the vacuole?

Answer 12

Holds sap and stores dissolved sugars, mineral ions and other substances.

Question 13

What is a tissue?

Answer 13

Groups of similar cells that work together to carry out the same job. An example is the human muscle tissue.

Question 14

What are organs?

Answer 14

Groups on tissues that work together to perform a more complicated function. Muscle is a tissue that creates a human heart.

Question 15

What are organ tissues?

Answer 15

Groups of organs that carry out a function essential to life, (e.g. circulation of blood around the body.

Question 16

What are stem cells?

Answer 16

Cells that can replicate itself or differentiate into many cell types.

Question 17

How does a stem cell turn into a specialised cell?

Answer 17

Stems cells are constantly replicating themselves and some of the cell that are replicated may differentiate (Develop new features) to become specialised cells - cells with the structures and proteins needed to carry out specific jobs in the organism.

Question 18

What does a red Blood cell do? What unique features does it have?

Answer 18

Function: To transport oxygen in the blood.
- Contains Haemoglobin - binds to transport oxygen
- No nucleus - more space for Haemoglobin
- Shaped so larger surface area - oxygen can enter and leave the cell more rapidly.

Question 19

What is an enzyme?

Answer 19

A biological catalyst.

Question 20

What is a catalyst?

Answer 20

A chemical which increases the rate of a reaction without being used up itself in the reaction.

Question 21

What is the Substrate?

Answer 21

The Molecule being reacted with the enzyme.

Question 22

What is the active site?

Answer 22

The part of the enzyme which is complimentary to the substrate. Only works if they are complimentary. E.G. a lock and key

Question 23

What is the lock and Key theory?

Answer 23

The theory that matches the same situation with enzymes and substrates.

Question 24

What affects the rate of an enzyme controlled reaction?

Answer 24

Temperature - Increases Kinetic energy so they move faster and there are more successful collisions.
High Temperature and Changes of Ph disrupt forces between Amino Acids in chains and this changes the shape of the enzyme. This is when it is denatured and the substrate will no longer fit into the active site.

Question 25

What are the adaptations for a red blood cell?

Answer 25

They are shaped as a biconcave disc - larger surface area so that oxygen can diffuse more rapidly.
Have no nucleus - more space for haemoglobin.

Question 26

What are the adaptations for a sperm cell?

Answer 26

Have a flagellum - allows it to swim, lots of mitochondria - provides energy needed for swimming.