organistion (B3,B4,B7)

Question 1

What is a tissue?

Answer 1

A tissue is a group of cells with a similar structure and function.

Question 2

Define an organ.

Answer 2

An organ is a group of tissues working together for a specific function.

Question 3

What are organ systems?

Answer 3

Organ systems are groups of organs that work together to form organisms.

Question 4

List the three main components found in foods.

Answer 4

• Carbohydrates
• Proteins
• Lipids

Question 5

Why can’t large molecules be absorbed into the bloodstream?

Answer 5

They are large molecules, so they have to be digested into smaller molecules.

Question 6

What begins the digestion of starch in the mouth?

Answer 6

Enzymes in saliva.

Question 7

What role does the stomach play in digestion?

Answer 7

Enzymes begin the digestion of proteins and hydrochloric acid helps the enzymes.

Question 8

What is the churning action of the stomach?

Answer 8

It turns food into a fluid, increasing the surface area for enzymes to digest.

Question 9

What does the pancreas release?

Answer 9

Enzymes that continue the digestion of starch and proteins and start the digestion of lipids.

Question 10

What is the function of bile released by the liver?

Answer 10

It speeds up digestion of lipids and neutralizes the acidity from the stomach.

Question 11

What happens in the small intestine regarding digestion?

Answer 11

Dare walls release enzymes to continue digestion of proteins and lipids. Small food molecules are absorbed into the bloodstream.

Question 12

What is absorbed in the large intestine?

Answer 12

Water is absorbed into the bloodstream.

Question 13

What is released from the body after digestion?

Answer 13

Faeces.

Question 14

What is the function of enzymes?

Answer 14

Enzymes catalyse chemical reactions.

Question 15

What is the active site of an enzyme?

Answer 15

A groove on the enzyme’s surface.

Question 16

What breaks down proteins?

Answer 16

Proteases.

Question 17

Where are proteases found?

Answer 17

In the stomach, pancreas, and small intestine.

Question 18

What breaks down carbohydrates?

Answer 18

Carbohydrases.

Question 19

What enzyme breaks down starch?

Answer 19

Amylase.

Question 20

Where is amylase found?

Answer 20

In saliva and pancreatic fluid.

Question 21

What does a lipid molecule consist of?

Answer 21

A molecule of glycerol attached to three molecules of fatty acids.

Question 22

What enzyme breaks down lipids?

Answer 22

Lipase.

Question 23

Where is lipase found?

Answer 23

In the pancreas and small intestine.

Question 24

What is bile made from?

Answer 24

Liver

Bile is produced in the liver and stored in the gallbladder.

Question 25

What role does bile play in digestion?

Answer 25

Speeds up the digestion of lipids but is not an enzyme ## Footnote Bile emulsifies lipids, increasing the surface area for digestion.

Question 26

What does bile do to lipid droplets?

Answer 26

Emulsifies them ## Footnote Emulsification increases the surface area of lipid droplets.

Question 27

What is the pH nature of bile?

Answer 27

Alkaline ## Footnote Bile neutralizes stomach acid, which increases the rate of lipid digestion.

Question 28

What theory explains enzyme specificity?

Answer 28

Lock and key theory ## Footnote This theory states that the substrate must fit perfectly into the active site of the enzyme.

Question 29

What happens to an enzyme's activity at high temperatures?

Answer 29

The enzyme becomes denatured ## Footnote High temperatures cause the enzyme molecule to vibrate, changing the shape of the active site.

Question 30

What is the effect of temperature on enzyme activity?

Answer 30

Optimum temperature ## Footnote Each enzyme has an optimum temperature at which its activity is maximized.

Question 31

What happens to enzyme activity if the pH is too acidic or alkaline?

Answer 31

Activity drops to zero ## Footnote The active site denatures under extreme pH conditions.

Question 32

What structural change occurs to enzymes at high temperatures?

Answer 32

Shape of the active site changes ## Footnote This change can lead to loss of function, known as denaturation.

Question 33

why is the small intestine so long

Answer 33

provides a large surface area

Question 34

what are villi and what do they do

Answer 34

increase the surface area for absorption of molecules in the small intestine have microvilli to increase the SA even further good blood supply so bloodstream rapidly moves products of digestion thin membrane for short diffusion path

Question 35

how many chambers does the heart have and what are their names

Answer 35

4 Right ventricle Right atrium Left ventricle Left atrium

Question 36

what do ventricles do

Answer 36

stop the blood flowing backwards

Question 37

Why does the left side of the heart have a thicker muscular walls

Answer 37

Has to pump blood around the whole body

Question 38

what is the resting heart rate controlled by

Answer 38

Pacemaker

Question 39

Why do coronary arteries spread to the heart muscle

Answer 39

to provide oxygen for respiration for energy for contraction