Test 2

Question 1

Food supplies organisms with…

Answer 1

-raw material for growth and repair
-energy for the cells -> metabolism
-resources needed to fight against disease and stay healthy

Question 2

Two types of nutrition

Answer 2

-autotrophic
-heterotrophic

Question 3

“A balanced diet provides all the…

Answer 3

“A balanced diet provides all the nutrients, in the correct amounts, needed to carry out the life process”

Question 4

The opposite of balanced diet

Answer 4

Mal nutrition

Question 5

What is rickets

Answer 5

Softening and weakening of bones because of malnutrition

Question 6

What causes rickets

Answer 6

lack of vitamin D and Calcium

Question 7

What is a balanced diet?

Answer 7

Provides all the nutrients in correct amounts needed to carry out the different life processes

Question 8

What does a balanced diet consist of?

Answer 8

1. lipids
2. carbohydrates
3. proteins
4. (Nucleic acids)
5. vitamins and minerals (needed in small amounts, essential for the efficient use of other nutrients)

Question 9

What percentage of water is in the human body?

Answer 9

+- 70%

Question 10

Why is water needed?

Answer 10

-Important for transporting substances/metabolism
*you need at least 1.5 litres of water per day

Question 11

What is fibre

Answer 11

The indigestible part of vegetables, cellulose -> cell wall

Question 12

What do we need fibre for?

Answer 12

It’s important for digestion by stretching the muscle of the gut and helping the food along
*shortage of fibre = constipation

Question 13

How is energy measured?

Answer 13

Joules or Calories

• 1 calorie = 4.2 J

Question 14

What are the three main energy providing organic molecules?

Answer 14

Fats - 39 kj/g
Carbohydrates - 17 kj/g
Proteins -20 kj/g

Question 15

Energy is needed for metabolic reactions, depending on 3 factors. What are they?

Answer 15

Basal metabolic rate
Activity or exercise
Digestion, absorption and storage of nutrients

Question 16

What is the basal metabolic rate

Answer 16

The process of staying alive (thinking, breathing, temperature regulation, circulation)

Question 17

What are factors influencing nutritional needs?

Answer 17

1.Age
2.gender
3.weight and height
4.growth periods
5.physical activity
6.pregnancy

Question 18

Salivary glands

Answer 18

Produce saliva -> H2O, amylase

Question 19

Action of pushing food and water down to organs

Answer 19

Peristalsis

Question 20

What is mechanical digestion

Answer 20

-By teeth and tongue
- by stomach movements (food mixed)

Question 21

What is chemical digestion

Answer 21

By enzymes (WS3)

Question 22

Hydrolysis

Answer 22

Enzymes convert large, complex molecules into small, soluble molecules which can be absorbed

Question 23

Absorption

Answer 23

-Most of the absorption of the nutrients into the blood or lymph takes place in the ileum ( 3 part of small intestine)

Question 24

Absorption -> adaptions of the ileum to its functions

Answer 24

1. Very long (5m) -> enough time for absorption
2. Highly folded surface (longer surface area for absorption)
3. Villi
4. Micro villi
5. epithelium only one of a cell thick -> short distance for absorption
6. capillaries in the villus

Question 25

Absorption -> adaptions of the ileum to its functions pt2

Answer 25

1.capillaries in the villus -> fast absorption of nutrients into the blood stream/ lacteal -lymphatic system 2.absorption of water: in the colon 3.storage of faeces until defecation: in rectum

Question 26

important functions of the liver

Answer 26

-absorbs food nutrients (amino acids and glucose) are first sent to the liver via hepatic portal vein -liver sorts out these molecules and provides them in ideal concentrations to the different parts of the body

Question 27

define human respiratory system

Answer 27

breathing is a biophysical process involving inhaling and exhaling to supply the respiratory system with O2 for -> cellular respiration

Question 28

Gas exchange in alveoli by diffusion:

Answer 28

movement of molecules from a high concentration to a low concentration

Question 29

LEARN DIFFUSION DIAGRAM

Answer 29

---------

Question 30

nostril

Answer 30

passageway for air

Question 31

nasal cavity

Answer 31

-filters lined with ciliated goblet cells (cellular?) - warms -moistures air

Question 32

mouth

Answer 32

passageway for air and food

Question 33

pharynx

Answer 33

common passage way for food and air

Question 34

epiglottis

Answer 34

covers the larynx

Question 35

larynx

Answer 35

air passes through here during breathing. when breathing out, the vocal can be made to vibrate. The sound produced create our speech.

Question 36

trachea

Answer 36

tube that carries air towards the lungs. C-shaped rings of cartilage prevent the trachea collapsing during inhalation.

Question 37

bronchus

Answer 37

first branch from the trachea. There is one bronchus to each lung

Question 38

bronchiole

Answer 38

final, very fine branch leading into alveolus

Question 39

alveoli

Answer 39

these are lined by the membranes where gas exchange takes place. The surface is moist, thin and has an enormous area. *in humans the total surface area is about as big as a tennis court

Question 40

diaphragm

Answer 40

helps you inhale and exhale

Question 41

homogenus

Answer 41

a mixture/ a solution

Question 42

pepsin

Answer 42

breaks down food acids act as a disinfectant for food in you stomach

Question 43

saliva

Answer 43

contains salivary amylase to digest starch/ polysaccharides into maltose (dissach.), mucus to lubricate food and hydrogen carbonate (alkaline) -> ideal ph for amylase to work

Question 44

what is the best approximate ph for amylase to work

Answer 44

alkaline

Question 45

gastric juice

Answer 45

-hydrochloric acid (HCl) provides acidic conditions (ph2) for pepsin and kills microorganisms -mucus protects the wall of the stomach from HCl

Question 46

pancreatic juice

Answer 46

container enzymes (proteases, lipases, amylases) and hydrogen carbonate which neutralises the acidity from the stomach to ph8

Question 47

bile

Answer 47

emulsifies the fats: converts them from large globules to smaller droplets, giving greater surface area for lipases to attack

Question 48

why is diffusion simple

Answer 48

-Simple diffusion does not require energy *Diffusion is a type of transport that simply occurs when there is a concentration difference where the molecules move from a region of higher concentration to a region of lower concentration