B1 biology

Question 1

what is a eukaryotic cell?

Answer 1

a cell which has a nucleus

Question 2

what happens in the cytoplasm?

Answer 2

where the main chemical reactions of the cell take place

Question 3

what is the cell wall made from?

Answer 3

cellulose

Question 4

what is a specialized cell?

Answer 4

a cell made to have a specific job or function

Question 5

what specialized cells are found in the small intestine?

Answer 5

Vili -

absorb nutrients through the feed you eat and send it where it’s needed

Question 6

explain why it is important for egg and sperm cells to have a haploid nucleus

Answer 6

it is important because both cells should contain 23 pairs of chromosomes in the haploid

Question 7

how are cilia cells used in the body ?

Answer 7

cilia cells help sweep dust, mucus and bacteria to the back of the throat so it can be swallowed

Question 8

what does cell surface membrane do?

Answer 8

controls what is allowed in and out of the cell, like, liquids and holds in the cytoplasm

Question 9

starch test

Answer 9

uses Iodine solution

negative test - remains yellow

positive test - turns blue/black

Question 10

reducing sugars

Answer 10

uses benedict solution

negative result - bright blue

positive result - green/yellow or orange / red

Question 11

proteins

Answer 11

uses Biurets reagent

negative test - light blue

positive test - purple

Question 12

fats

Answer 12

Emulsion test - add a few drops of ethanol and shake.
then add a few drops of water and then shake.

negative test - remains clear

positive test - cloudy

Question 13

what is the diffrence between quantitive and Qualitative ?

Answer 13

Qualitative - shows if a substance is present or not

Quantitive - shows how much of that substance there is

Question 14

why are Enzymes known as Catalysts ?

Answer 14

because they speed up the rate of reaction so that they have a more comfortable tempreture to live at (optimum)

Question 15

what is the molecule acted on by the enzyme called

Answer 15

the ‘substrate’

Question 16

what is the part of the enzyme called where it meets the substrate?

Answer 16

the active site

Question 17

what happens at optimum tempreture ?

Answer 17

the rate of reaction is at it’s fastest because the most kinetic energy is created in the reaction

Question 18

what happens when enzymes denature ?

Answer 18

they become no longer complementry to their active site

Question 19

why does substrate concentration plateu in the rate of reaction at times?

Answer 19

sometimes when you have more substrates than active sights in reaction the substrate concentration will plateu

Question 20

rate of reaction =

Answer 20

amount of substrate used or amount of product formed / time taken

Question 21

what is cellulose?

Answer 21

Cellulose is the main substance found in plant cell walls and helps the plant to remain stiff and strong.

Question 22

describe the process of diffusion

Answer 22

1) diffusion is when particles of liquids and gas are constantly moving.

2) this causes an overall movement of particles from an area of higher concentration to an area of lower concentration.

Question 23

how does diffusion occur in plant cells?

Answer 23

diffusion is the process that allows oxegen and carbon dioxide into and out of the cells

Question 24

describe the process of Osmosis

Answer 24

1) a partially permeable membrane allows molecules of a certain size to pass through it (like water and oxegen)

2) sugars and salts molecules are too big so they cannot pass through the membrane

Question 25

calculating mass % loss die to osmosis

Answer 25

change in mass = final mass - initial mass / initial mass x100