digestive system + respiration

Question 1

in which two part of the digestive system is starch broken into maltose

Answer 1

Mouth (salivary glands) and the duodenum (from pancreatic juices)

Question 2

In which part of the digestive system are lipids broken down into fatty acids and glycerol

Answer 2

The duodenum (made in liver and stored in gallbladder)

Question 3

In which part of the digestive system is maltose turned into glucose, and by which enzyme

Answer 3

The ileum, eith the enzyme maltase

Question 4

In which part of the digestive system are pepsides broken down into amino acids

Answer 4

The ileum

Question 5

Describe and explain three things that happen in the stomach

Answer 5

Mechanical break down of food by churning
Protein broken into pepsides by pepsin
Hydrcholic acid kills bacteria

Question 6

Describe and explain what happens in the duodenum

Answer 6

-Further digestion
Where Pancreas releases juices containing enzymes which break down starch into maltose and proteins into pepsides
-Emulsification of bile, turning large liquid droplets into an emulsion of smaller droplets
- pancreatic juices and bile together make alkaline condition which neutralizes bolus

Question 7

Describe and explain what happens in the ileum and how

Answer 7

-Absorption of nutrients into the blood stream and assimilaition of them into where they are needed
-small intestine is long, has villi, and is semi permeable

Question 8

Describe and explain six adaptations of the villi which aid with absorption

Answer 8

1) large surface area- to increase rate of diffusion
2) thin layer of epithelial cells - short distance for nutrients to diffuse through
3) blood capillary network - oxyegn is transported in and waste products are transported out
4) microvilli on surface -to further increase the rate of diffusion
5) muscle layer- to help the villi contract and move the contents of the ileum along
6) good supply of blood- to maintain a concentration gradient between bloodstrean and ileum

Question 9

Describe and explain three adaptations of the ileum

Answer 9

Long and folded- to provide a large surface area
Contains villi- to increase the surface area
Semi permeable- to allow nutrients to diffuse through

Question 10

State what is meant by a balanced diet

Answer 10

A diet consisting of various components to maintain health in appropriate proportions

Question 11

What is the meaning of egestion

Answer 11

The process of the removal of undigested waste substances from the anus

Question 12

What is the meaning of assimilation and give a short description of the process

Answer 12

The movement of digested food into the cells of the body where they are used. Small molecules are used to make large food molecules

Question 13

What is the definition of a peristalisis

Answer 13

a series of wave like muscle contractions which move food through the digestive tract

Question 14

When the circular muscles are relaxed but the longitutdional muscles are contracted, what does the gut look lkke

Answer 14

The gut is wide

Question 15

What are the two role of bile

Answer 15

To emulsify fats by breaking them down from larger droplets into smaller droplets
And to neutralize the acidic food by providing it with alkaline conditions

Question 16

What PH do enzymes in the small intestine work best at

Answer 16

PH 8/9 (alkaline)

Question 17

What is the balanced symbol chemical equation for respiration

Answer 17

C6H12O6 + 6O2 ——-) 6CO2 + 6H2O + ATP

Question 18

What does oxygen debt mean

Answer 18

The amount of oxygen required to completely oxidise lactic acid built from anaerobic respiration

Question 19

What are four uses of ATP

Answer 19

Muscle contraction
Building large molecules
Cell division
Active transport

Question 20

When an athlete beguns to race, why does his breathing rate increase

Answer 20

Because his muscles are more moving faster,
so are respiring more and need more atp
Thus so he needs to provide more oxygen to his muscles and remove more carbon dioxide from them

Question 21

When an athlete is in the race, why does his heart rate begin to increase

Answer 21

Because he needs to transport more oxygen to his muscles
So amount of blood pumped per minute increases

Question 22

When an athlete begins to stop running, why is he still panting

Answer 22

Because he needs to repay the oxygen debt caused from the lack of oxygen during anaerobic respiration

Question 23

Explain why reducing the blood supply to the heart muscle cells can cause a heart attack

Answer 23

Less oxygen is being supplied
So less aerobic respiration
So body resorts to anaerobic respiration
Where a build up of lactic acid can cause the enzymes to denature as lactic acid is acidic

Question 24

What is the meaning of egestion

Answer 24

The removal of undigested food from the anus

Question 25

What are the five main processes of the digestuve system

Answer 25

Ingestion Digestion Absorption Assimilation Egestion

Question 26

What is digestion

Answer 26

The mechanical and chemicak break down of food, converting large insoluble molecules into smaller soluble ones

Question 27

Suggest the consequences of a diet that contains too much fat

Answer 27

Cholesterol and saturated fats can build up in the arteries Can lead to obesity Which can lead to hugh blood pressure, heart disease and diabetes

Question 28

Which two parts of the digestive system produce amalyse

Answer 28

Mouth and pancreas

Question 29

If i place lipid drops onto water Explain what would halpen in each case if i added: 1)bile 2)bile and lipase 3)boiled lipase 4)bile and protease

Answer 29

Droplets would become smaller but would not dissapear Droplets would dissapear Droplets would remain the same Droplets would become smaller but not dissapear

Question 30

If i place droplets of lipid onto a tray of water Explain why no droplets are seen after bile and lipase solution is added to the lipid and water mixture.

Answer 30

Bile emulsifies fats so increases the surface area Bile also neutralizes the acidic conditions of the food for the alkaline optimum temperature of the lipase Lipase is an enzyme which breaks down the bile into fatty acids and glycerol

Question 31

Describe what happens to fish protein in the stomach(4marks)

Answer 31

Mechanically DIGESTED as the stomach churns the protein Hydrochloric acid is released which kills bacteria Because of the hydrochloric acid, the optimum ph is 2 so food turns acidic And enzyme pepsin breaks down protein into peptides

Question 32

Why is it important to use sterile bottles to store yeast

Answer 32

To remove pathogens

Question 33

Why does the number of yeast cells decrease after fermentation

Answer 33

Yeast cells use up all the glucose to make ethanol Excess amount of ethanol killw yeast cells

Question 34

What is the word equation for fermentation

Answer 34

Glucose—-) carbon dioxode + ethanol. (NO ATP)

Question 35

Explain why the breathing rate is higher after intense excercose

Answer 35

Because the body has been respiring anaerobically, the lactic acid produced requires oxygen to oxidise it So the oxygen debt needs to be repaid

Question 36

What colour does carbon dioxide indicator turn when carbon dioxide is present

Answer 36

Orange to yellow

Question 37

Suggest why a cow(who eats grass) absorbs less percentage energy from repiration than a fish(who eats insects)

Answer 37

Because the grass contains cellulose which is difficult to digest

Question 38

If im boiling a test tube with water with a mounted needle of food underneath to meausure the energy contents of food, explain why the value obtained will be more accurate if a larger volume of water is used

Answer 38

It will have less surface area to volume ratio, so less heat will be lost

Question 39

In which two parts of the body does the enzyme pepsin break down protein into peptides

Answer 39

Stomach Duodenum

Question 40

The enzyme pepsin breaks_____ into _____ And the enzyme peptidase breaks _____ into_____

Answer 40

Pepsin breaks protein into peptides (trypsin also does this) Peptidase breaks peptide into amino acid

Question 41

If a patient produces hard and clumpy stool, what does this suggest about them?

Answer 41

They are constipated and have little water in their stool

Question 42

If a patient produces watery stool, what does this suggest

Answer 42

They have diarrhea or food poisoning

Question 43

Which organ releases insulin

Answer 43

The pancreas

Question 44

During a food test, why is it important that the food is frost crushed up and dissolved in water

Answer 44

To dissolve any soluble sugars

Question 45

Explain why in the lipid test a white layer will form

Answer 45

Ethanol is soluble in water so will dissolve, Leaving behind the insoluble lipid emulsion layer on top

Question 46

When investigating the energy content of food, why would dry food work best

Answer 46

Because it burns easily

Question 47

In the experiment to investigate the energy content in food, explain one thing that you could do to increase the accuracy of the value you get for heat energy

Answer 47

Insulate the boiling tube with aluminum foil for example to minimize heat loss

Question 48

Why does aerobic respiration produce more energy than anaerobic respiration

Answer 48

Because glucose is broken down completely, whereas in anaerobic respiration it is incomeoltelt broken down

Question 49

Why is anaerobic respiration favoured in short bursts of exercise

Answer 49

Because it uses less oxygen, this is because there is not enough time for enough oxygen to be breathed in to break down glucose as there is not enough oxygen available yet for the intensity of excerise

Question 50

Give five uses of energy in the body

Answer 50

-for active transport -to keep the body warm, and maintain a constant temperature -for muscle contraction and growth -for cell division -protein synthesis

Question 51

Give the word equation for the oxygen debt

Answer 51

Lactic acid + oxygen —-) carbon dioxide + water

Question 52

The hepatic portal vein transfers …. Blood form the… to the…

Answer 52

Deoxygenated Small intestine Liver