Organisation P1

Question 1

Denature

Answer 1

The active site of an enzyme changes its shape so that the substrate no longer fits (this is irreversible).

Question 2

Enzyme

Answer 2

A protein that is a biological catalyst which speeds up the rate of reactions.
(specific to substrate and active site)
(increase temp - enzyme activity increases , faster movement)
(greater frequency of collisions - increased rate of reaction)
(if temp reaches past optimum, enzyme denatures)

Question 3

Valve (heart)

Answer 3

Prevents blood from flowing backwards.

Question 4

Palisade Mesophyll

Answer 4

A tissue in a leaf with the greatest amount of chlorophyll, meaning photosynthesis occurs mostly here (produces glucose). (top of leaf)

Question 5

Spongy Mesophyll

Answer 5

Air pockets allow for diffusion of carbon dioxide into the leaf and oxygen is able to diffuse out.
(under pm)

Question 6

Stoma

Answer 6

They are gaps at the bottom of the leaf that open and closes to allow gasses to diffuse in and out.

Question 7

What does Amylase do?

Answer 7

Breaks down starch into simpler sugars such as glucose.

Question 8

Cells

Answer 8

Are the fundamental units of all living organisms.

Question 9

Organs

Answer 9

Are groups of tissues that work together to perform a specific function.
(e.g the stomach contains muscle tissue and glandular tissue which releases enzymes)

Question 10

Tissues

Answer 10

Are groups of cells that act together to perform a similar structure and function

Question 11

The stomach is composed of three types of tissues. What are these?

Answer 11

Muscular (moves contents around during digestion).
Glandular (produces digestive juices that breaks down the stomach’s contents).
Epithelial (lines the stomach).

Question 12

Mesophyll tissue

Answer 12

Capable of photosynthesis

Question 13

Epidermal Tissue

Answer 13

Plants’ waxy outer layer.

Question 14

Organ Systems

Answer 14

a group of organs that work together to form organisms (e.g digestive system)

Question 15

Organism

Answer 15

The highest level of organisation in a multicellular organism, consisting of several organ systems.

Question 16

Abundant water

Answer 16

Lots of available water

Question 17

Guard Cells

Answer 17

Responsible for opening and closing the stoma.

Question 18

Equation for gradients (rate if reaction is equal to)

Answer 18

change in y divided by change in x

Question 19

Equation for reaction rate

Answer 19

change in mass divided by change in time

Question 20

3 main digestive enzymes and what they break down

Answer 20

amylase -> (a type of carbohydrase that breaks down starch)
protease -> protein
lipase -> lipids (fats)

Question 21

Meristem tissue and where it is found

Answer 21

Makes unspecialised cells that have the potential to become specialised (found in tip of roots)

Question 22

Pacemaker

Answer 22

Controls the heart rate to treat abnormal heart rhythms.

Question 23

what is the role of the small intestine and how is it adapted

Answer 23

products from digestion absorbed into bloodstream in small intestine, has large surface area and muscular contraction to churn up food

Question 24

where is insulin made?

Answer 24

pancreas

Question 25

3 main nutrients (large molecules)

Answer 25

lipids (fats)
protein
carbohydrates (starch and glucose)

Question 26

During digestion…

Answer 26

• large food molecules (lipids, carbohydrates and proteins) are broken down into small molecules by enzymes
• the small molecules can then be absorbed into the bloodstream

Question 27

During digestion…

Answer 27

• large food molecules (lipids, carbohydrates and proteins) are broken down into small molecules by enzymes
• the small molecules can then be absorbed into the bloodstream

Question 28

After Digestion, what happens?

Answer 28

• products of digestion are used by body to build new carbohydrates, lipids and proteins
• some of the glucose produced is used in respiration

Question 29

Digestive System steps

Answer 29

1) mouth -> food is chewed, enzymes in saliva begin to digest starch into smaller sugar molecules
—–> oesophagus
2) stomach -> hydrochloric acid which helps enzymes digest proteins(several hours)
-churning action of stomach muscles turns food into a fluid, increasing the surface area for enzymes to digest
3) liver and pancreas
liver : releases bile which helps to speed up digestion of lipids , neutralises acids released from stomach
pancreas: releases enzymes which continue digestion of starch and proteins (also begins digestion of lipids)
4) travels down small intestine -> walls release enzymes to continue digestion of proteins and lipids, small food molecules absorbed into bloodstream via diffusion or active transport
5) large intestine -> water absorbed into bloodstream + faeces released by body

Question 30

what causes an enzyme to denature (temp)

Answer 30

1) at too high temps (past optimum) enzyme molecule vibrates
2) changes the active site so substrate no longer fits (becomes denatured)

so enzyme can no longer catalyse reaction

Question 31

what are proteins/ how do proteases digest them/where are they

Answer 31

=long chain amino acids

Protease enzymes convert protein back to INDIVIDUAL amino acids, which are absorbed into bloodstream. When amino acids absorbed by blood cells they join together in a different order = human proteins

(found in stomach, pancreatic fluid, small intestine)

Question 32

what is starch/ how do carbohydrases (specifically amylase) digest them /where

Answer 32

= starch is a carbohydrate consisting of a chain of glucose molecules

Amylases digests starch into simple sugars.

(found in saliva, pancreatic fluid)

Question 33

what are lipids/ how do lipase digest them/ where?

Answer 33

= lipids consist of a molecule of glycerol attached to 3 molecules of fatty acids

Lipase digests the glycerol and fatty acids, also involves bile to digest lipids

(pancreatic fluid, small intestine)

Question 34

Bile - made? stored? converts? emulsifies? neutralisation?

Answer 34

BILE IS NOT AN ENZYME
made in liver
stored in gallbladder
helps to speed up digestion pf lipids

bile converts large lipid droplets into smaller droplets
bile EMULSIFIES the lipid (massively increasing the surface area of lipid droplets, increasing the rate of lipid breakdown by lipase )

bile is alkaline -> neutralises stomach acid to make alkaline conditions in small intestine , increasing the rate of lipid digestion by lipase

Question 35

human enzyme optimum temp

Answer 35

37 degrees celcius

Question 36

pH of an enzyme

Answer 36

if we make pH more acidic or alkaline then activity drops to zero because active site denatures if the conditions are too acidic or too alkaline

(acidic - protease
(alkaline - lipase)

Question 37

Food test beginning method

Answer 37

1) take food sample and grind this with distilled water using a mortar and pestle -> paste
2) transfer paste to a beaker and add more distilled water, stir so chemicals in food dissolve in water
3) filter solution to removes suspended food particles ( Not for lipids as they will stick to filter paper)

2cm^3 for each food solution in each beaker!