N5 Biology Unit 1 Cell Biology

What is the function of a cell wall?

It supports, protects and maintains the shape of cell

What type of organisms are cell walls found in?

Plant, fungi and and bacteria

What is the function of the mitochondria?

Site of aerobic respiration

What type of organisms are mitochondria found in?

Plant, animal and fungi

What is the function of chloroplasts?

Site of photosynthesis

What type of cell are chloroplasts found in?

Green plant cells

What is the function of the cell membrane?

Controls entry and exit of substances

What type of organisms are cell membranes found in?

Plant, animal, fungi and bacteria

What is the function of the sap vacuole?

Stores water, sugar and salts

What type of organisms are sap vacuoles found in?

Plant

What is the function of the nucleus?

Controls the activities of the cell and contains genetic material.

What type of organism doesn't have a true nucleus?

Bacteria

What is the function of the ribosomes?

Site of protein synthesis

What is the function of plasmids?

Code for synthesis of a few proteins not coded for by the bacterial chromosomes

What type of organisms are plasmids found in?

Bacterial cells

What is the function of the of the cytoplasm ?

The site of chemical reactions

What is the cell wall of plants made of?

Cellulose

What is the cell membrane made of?

Phospholipids and proteins

What is passive transport?

The movement of of substances/molecules which does not need an input of energy down a concentration gradient.

Is diffusion an example of passive or active transport?

Passive transport

What is osmosis?

Osmosis is the movement of water down a concentration gradient across a selectively permeable membrane

Can animal cells burst?

Yes

What is active transport?

Active transport is the movement of substances against the concentration gradient

What supplies the energy needed for active transport?

ATP

What is the process in which cells are made called?

Cell division

Why is cell division important?

For growth, repair and asexual reproduction

What is the other name for sex cells?

Gametes

What form of nuclear division is involved in the process of growth and repair?

Mitosis

What is the chromosome complement?

The number of chromosomes present in a cell.

Why is the chromosome compliment said to be diploid?

Because it contains two sets of a number of chromosomes

Why is it so vital that mitosis maintains the chromosome compliment of cells?

So that the new cells formed have the same information as the original cell.

What do chromosomes contain?

Genetic information that gives an organism its characteristics

What is cell culture?

The deliberate growth of cells under lab enforced conditions

For optimum growth what mediums do cell need?

- Nutrients

- Gases

-Suitable PH

-Minerals and vitamins

- Water

Why does cell culture need to be carried out in aseptic conditions?

To avoid growing unwanted cells

What are the four bases?

Adenine, thymine, guanine and cytosine.

How does the DNA differ from one member of a species to the next?

The order of the bases

What is mRNA?

A molecule which makes a complimentary copy of the code from the DNA in the nucleus. The mRNA strand copies the code for a particular protein

Where does the mRNA strand travel after it leaves the nucleus?

To a ribosome in the cytoplasm

What does the mRNA code for?

Amino acids

What is the function of enzymes?

Biological catalysts produced by all living cells: they speed up chemical reactions without being used up

What is an example of an enzyme?

Phosphorylase synthesises starch from glucose-1-phosphate

Catalase changes hydrogen peroxide into oxygen and water

What is the function of hormones?

Chemical messengers transported in the blood

Insulin controlling blood glucose level is an example of what?

Hormones

Providing defence against specific bacteria and viruses is the function of what?

Antibodies

What is the function of structural proteins?

Provide strength and support for cell structures

Keratin in hair and nails is an example of what type of protein?

Structural

What is the function of receptors?

Allow cells to recognise specific chemicals

What is a substrate?

The particular substance on which a particular enzyme works

What is the active site?

The place on the enzymes surface which is complimentary in shape to its substrate

What is the function of structural proteins?

Provide strength and support for cell structures

What is the function of receptors?

Allow cells to recognise specific chemicals

What is a substrate?

The particular substance on which a particular enzyme works

Why can animal cells burst?

Because they don't have a cell wall to support them

What is enzyme specificity?

One enzyme - one reaction

What is a degradation reaction?

The breakdown of a large molecule to smaller molecules

What is a synthesis reaction?

The manufacture of a large molecule from a small

What is an example of degradation reactio?

Amylase breaks down starch to maltose

What are optimal conditions for enzyme action?

The pH and temperature at which the enzyme works best.

What is the effect of high temperature on enzymes?

The structure is changed permanently, denature for the enzymes and making it so they are unable to do their job.

What is genetic engineering?

The artificial transfer of genetic information into cells

What are some examples of GM organisms?

- Tomatoes with a longer shelf life

- Blight resistant potatoes

- Birds resistant to bird flu

What are some products from GM organisms?

- Insulin (produced by bacteria)

- Growth hormone (produced by bacteria)

- Vaccines (produced by hens)

What's stage one of genetic engineering?

Gene probes can be used to identify the section of DNA that contains the required gene. The required gene is cut out using restriction enzymes.

In what stage of genetic engineering is the plasmid removed from a bacterial cell and cut with restriction enzyme?

Stage two

What is stage three of genetic information?

The required gene is inserted into the plasmid

In what stage does of genetic information is the plasmid, which now contains the required gene inserted back into the bacterial cell?

Stage 4

What is stage 5 of genetic engineering?

The bacterial cell is grown in optimum conditions where it replicates rapidly producing a population of cells each containing a copy of the required gene.

What is the final stage of genetic engineering?

The required gene produces the product

What is respiration?

A series of enzyme controlled reactions

What happens during respiration?

Glucose is chemically broken don in a series of reactions, each controlled by a different enzyme.

What does ATP stand for?

Adenosine triphosphate

What is the summary equation for aerobic respiration?

Glucose + oxygen ----------------> co2 +water

ADP +pi--->ATP

What are some examples of cellular activities which require ATP

-Muscle cell contraction

- Cell division

-Protein synthesis

- Transmission of nerve impulses

- Active transport

How many ATP molecules are produced in aerobic respiration per glucose molecule?

38

Where does aerobic respiration start?

The cytoplasm

Where does aerobic respiration end?

The mitochondria

What is fermentation?

The breakdown of glucose in cells in the absence of oxygen

What is pyruvate converted to in plants during fermentation?

Ethanol and carbon dioxide

What is pyruvate converted to in animals during fermentation?

Lactic acid

How many molecules of ATP are produced per glucose in fermentation?

2

Where does fermentation occur?

In the cytoplasm