Human Health & Systems

Question 1

Stages of nutrition

Answer 1

Ingestion / eating: food is taken in by the body
Digestion: food is broken down
Absorption: digested food passes into the bloodstream
Assimilation: using the food in the cells of the body
Elimination: getting rid of indigested food

Question 2

Ingestion / eating:

Answer 2

food is taken in by the body

Question 3

Absorption

Question 4

Physical digestion

Answer 4

• taking large pieces of food and breaking them down into smaller pieces

Happens in the •mouth (teeth) and •

Question 5

Chemical digestion

Answer 5

Involves the use of chemicals called enzymes to break down food

Enzymes are chemicals that speed up reactions without being used up in the reaction

Enzymes act on a substrate and breaks it down into a product

Example: substrate = starch,, Enzymes = amylase (saliva),, Product = maltose (sugar)

Question 6

enzymes

Answer 6

Enzymes are chemicals that speed up reactions without being used up in the reaction

Question 7

Chemical digestion

Answer 7

• amylase in mouth
• enzymes in the stomach
• most chemical digestion happens in the small intestine
• bile made in liver to break down fats
• pancreas makes digestion juices which contain enzymes

Question 8

In a cigarette

Answer 8

• Acetone
• Mercury
• Lead
• Nicotine
• Cadmium
• Carbon Monoxide
• Hydrogen Cyanide
• Urethane
• Arsenic
• Phenol
• Formaldehyde
• DDT

Question 9

Anaerobic Respiration

Answer 9

does not use
oxygen to release energy from food.

Question 10

Aerobic Respiration

Answer 10

needs oxygen to
release energy from food.

Question 11

How does Oxygen get to our
Cells??

Answer 11

• Oxygen is carried by the haemoglobin in
red blood cells to all other cells of the body

Question 12

Remember!

Answer 12

Much less energy is released from food by
Anaerobic Respiration than by Aerobic
Respiration.

Question 13

Examples of anaerobic respiration

Answer 13

• Yeast converts sugars to alcohol in
“Fermentation” – this produces alcohol for
drinks such as beers and wine

Question 14

Did you know ???s

Answer 14

When you get a cramp whilst exercising it is
caused by the acid that your cells produce when
they respire anaerobically (without oxygen).
• the only reason they do this is because your body
needs to produce so much energy while you
exercise that not enough oxygen reaches the cells
on time.
• To try to sort this out you start breathing fast and
get out of breath as your lungs are trying to take in
as much oxygen as possible!!

Question 15

Now to test for Carbon Dioxide!

Answer 15

• Limewater turns cloudy in the presence of
Carbon Dioxide.
• What happened when you breathed into
limewater??
• What does this tell you??

Question 16

Breathing

Answer 16

As you can see from the Equation Oxygen
and food are the two important things our
cells need to give us energy.
• We’ve learned how the food gets to our
cells by digestion.
• The oxygen gets to our cells by breathing!

Question 17

Pharynx

Answer 17

This is the scientific name for your throat
area.

Question 18

Trachea

Answer 18

This is the tube that leads into your lungs.
• It is very strong and is kept open by Rings
of Cartilage.
• If we didn’t have rings of cartilage what do
you think might happen??

Question 19

Bronchus

Answer 19

As we have two lungs our Trachea divides
to branch into each one.
• These two branches are called Bronchi.

Question 20

Bronchioles

Answer 20

To spread out through all our lungs the
bronchi break up to even smaller little
branches called BRONCHIOLES.

Question 21

Alveoli

Answer 21

The final place the air we breathe in goes to
in our lung is the ALVEOLI.

It is in the Alveoli that Carbon Dioxide is
brought into the lungs to be exhaled and
oxygen is brought into the body for
respiration.
• This is called Gas excha

Answer 22

• It is in the Alveoli that Carbon Dioxide is
brought into the lungs to be exhaled and
oxygen is brought into the body for
respiration.
• This is called Gas exchange. Why do you
think it is called this?