Topic 1-key Concepts In Biology

Question 1

What are all living things made up of?

Answer 1

Cells

Question 2

What si a eukaryotic cell?

Answer 2

Cells which have a nucleus eg plant and animal cells

Question 3

What is a prokaryotic cell?

Answer 3

Cells which DON’T have a nucleus eg bacteria cell

Question 4

Function of the nucleus

Answer 4

Contains DNA and controls activities of the cell

Question 5

Function of the cell membrane

Answer 5

Controls what goes in and out of the cell

Question 6

Function of the ribosome

Answer 6

Protein synthesise

Question 7

Function of the mitochondria

Answer 7

Where aerobic respiration occurs

Question 8

Function of the cytoplasm

Answer 8

Where chemical reactions take place

Question 9

Function of the chloroplast

Answer 9

Contains chlorophyll to absorb sunlight- photosynthesis happens here

Question 10

Function of the vacuole

Answer 10

Keeps the cell rigid and stores sap

Question 11

Function of the cell wall

Answer 11

Made of cellulose for support and stop the cell bursting

Question 12

What features are found in a animal cell

Answer 12

Nucleus
Cytoplasm 
Cell membrane
Mitochondria
Ribosome

Question 13

What features are found in a plant cell

Answer 13

Nucleus
Cytoplasm 
Cell membrane
Mitochondria
Ribosome
Rigid cell wall
Vacuole 
Chloroplast

Question 14

Subcellular structures of a bacteria cell

Answer 14

Chromosomal DNA 
Ribosome
Cell membrane 
Plasmid DNA
flagellum

Question 15

Function of the chromosomal DNA

Answer 15

One long circular chromosome
Controls the cell’s activities and replication
It floats free in the cytoplasm (not in the nucleus)

Question 16

Function of the flagellum

Answer 16

A long hair like structure that roadsters to make the bacterium move. Can be used to move the bacteria away from harmful substances like toxins

Question 17

Function of the plasmid DNA

Answer 17

Small loops of extra DNA that aren’t part of the chromosome

Plasmids contain genes for things like drug resistance and can be passed between bacteria

Question 18

What are specialised cells

Answer 18

Cells that have a structure which makes the: adapted to their function

Question 19

Haploid cell meaning

Answer 19

Has half the amount of chromosome

Question 20

How has an egg cell adapted (specialised) for it’s function

Answer 20

1) contains nutrients in the cytoplasm to feed the embryo
2) has a haploid nucleus
3) straight after fertilisation, it’s membrane changes structure to stop any more sperm getting in, to make sure the embryo ends up with the right amount of DNA

Question 21

How has a sperm cell adapted (specialised)for it’s function

Answer 21

1) sperm cell has a long tail so it can swim to the egg
2) has lots of mitochondria in the middle section to provide the energy (from respiration) needed to swim this distance
3) has an acrosome at the front of the “head” where it stores enzymes needed to digest its way through the membrane of the egg cell
4) haploid nucleus

Question 22

The function of cilliated epithelial cells

Answer 22

To move substances
The cilia beat to move substances in one direction, along the surface of tissue
Eg lining of airways

Question 23

Meaning of resolution

Answer 23

How well a microscope distinguishes between two points that are close together

Question 24

Info about light microscopes

Answer 24

Invented in 1590’s
They work by passing light through the specimen
Allow us to see the nucleus and mitochondria

Question 25

Info about electron microscopes

Answer 25

Invented in the 1930’s
Use electrons rather than light
Have a higher magnification and resolution than light microscopes
Allow us to see internal structures of mitochondria and chloroplast

Question 26

What is a enzyme

Answer 26

Is a protein that acts as a biological Catalysts, that speed up the rate of a breakdown or synthesis reactions whilst remaining chemically unchanged

Question 27

Explain lock and key theory

Answer 27

The active site and the substrate when joined fit together like a lock and key
If the substrate’s shape doesn’t fit into the active site then the reaction won’t be catalysed

Question 28

Effect of temperature on enzymes

Answer 28

It changes the rate of an enzyme catalysed reaction
As the temperature (from 0°C) the rate increases
When it reaches it’s OPTIMUM TEMPERATURE some of the bonds holding the enzyme together break
This changes the shape of the enzymes active site, so the substrate won’t fit
Enzyme is DENATURED

Question 29

Effect of pH on enzymes

Answer 29

If the pH is too high or low the pH interferes with the bonds holding the enzyme together
Changes the shape of the active site and denatures the enzyme

Question 30

Effect of concentration on the enzyme

Answer 30

The higher the substrate concentration, the faster the reaction.
Because it is more likely that the enzyme will meet up and react with a substrate molecule
If there are so many substrate molecules the enzymes can’t cope with anymore

Question 31

Enzyme:Carbohydrases

Answer 31

Convert carbohydrates into simple sugars

Question 32

Type of carbohydrases

Answer 32

Amylase
Breaks down starch into simple sugars
Present in the saliva or pancreas

Question 33

Enzyme: pro teases

Answer 33

Enzymes that break protein down into amino acids

Question 34

Type of protease

Answer 34

Pepsin

Made in stomach (low pH)

Question 35

Enzyme: lipases

Answer 35

Enzymes that break lipids down into fatty acids and glycerol

Question 36

Diffusion meaning

Answer 36

The passive movement of molecules form an area of high concentration to an area of low concentration(down concentration gradient)

Question 37

Osmosis meaning

Answer 37

The passive movement of water molecules from an area of high concentration to an area of low concentration (down the concentration gradient) through a partially permeable membrane

Question 38

Active transport meaning

Answer 38

The movement of molecules from an area of low concentration to an area of high concentration (against the concentration gradient) requiring energy from respiration