SB1

Question 1

How do you work out a microscopes magnification?

Answer 1

Eyepiece lens * objective lens

Question 2

Resolution

Answer 2

The smallest distance between two points that can still be seen as two points

Question 3

Electron microscopes?

Answer 3

Before 1930s. Shoot beams of electrons. these microscopes can magnify up to x2 000 000.

Question 4

What is a eukaryotic cell

Answer 4

A cell with a nucleus

Question 5

Cell membrane

Answer 5

A very thing bag. Controls what enters and leaves and separates one cell from another.

Question 6

Cytoplasm

Answer 6

Contains a watery jelly and is where most of the cell’s activity take place.

Question 7

Mitochondria

Answer 7

Jelly bean shaped structures in which aerobic respiration takes place.

Question 8

Ribosomes

Answer 8

These make protein for a cell.

Question 9

Nucleus

Answer 9

Controls the cell and its activity. Contains chromosomes which contain DNA.

Question 10

Specialized cells

Answer 10

They have a specific job. There are about 200 types of specialized cells in humans. All human cells have the same basic design but their sizes, shapes and sub-cellular structures are different so that they are adapted to their functions.

Question 11

What is a gamete

Answer 11

A specialized sexual reproduction cell that fuses with another gamete to develop and embryo.

Question 12

Haploid cells

Answer 12

A cell with one copy of each chromosome

Question 13

Diploid cells

Answer 13

Cells with two sets of chromosomes.

Question 14

Acrosome

Answer 14

The tip of the head of a sperm cell. It contains enzymes that break down the substances in the egg cell’s jelly coat.

Question 15

Flagellum

Answer 15

A tail which enables the cell to swim

Question 16

Prokaryotic cells

Answer 16

Do not have nuclei or chromosomes

Question 17

Amylase

Answer 17

Is found in saliva and the small intestine. It is to break down starch and small sugars (e.g maltose)

Question 18

Catalase

Answer 18

Found in most cells but especially liver cells. Breaks down hydrogen peroxide made in many cell reactions to water and oxygen.

Question 19

Biological catalyst

Answer 19

Speeds up rates of reaction (e.g breakdown of cells like digestion)

Question 20

Chemical reagents

Answer 20

Used in food tests to identify breakdown of cells

Question 21

Iodine

Answer 21

Changes from a yellow-orange colour to a blue-black colour when in contact with starch

Question 22

Benedicts solution

Answer 22

Mixed with food solution and placed in a hot water bath for a few minutes. No colour change = no reducing sugar, slight colour change = little reducing suga, orange = more reducing sugar, red = lots of reducing sugar.

Question 23

Active site

Answer 23

Where the substrate of the enzyme fits at the start of the reaction. Every enzyme can only work with a specific substrate.

Question 24

Changes in pH or temperature

Answer 24

Can affect the shape of the active site. This can cause the enzyme to no longer fit in it.

Question 25

Enzyme denature

Answer 25

When the active site is disfigured to the point where a substrate cant bind to it.

Question 26

Optimum temperature/pH

Answer 26

The temperature. pH at which an enzyme works the fastest.

Question 27

Diffusion

Answer 27

The movement of particles from an area of high concentration to an area of low concentration.

Question 28

Concentration gradient.

Answer 28

The difference between two concentrations forms a concentration gradient. The bigger the difference, the steeper the concentration and the faster diffusion occurs.

Question 29

Osmosis

Answer 29

The diffusion of small molecules (e.g water) through a semi-permeable membrane. Osmosis can cause tissues to gain or lose mass.

Question 30

Change in mass

Answer 30

final mass-initial mass/ initial mass *100

Question 31

Active transport

Answer 31

Cells transporting molecules against a concentration gradient. This is an active process so requires energy to carry out.