Food for Life - Chapter 10

Question 1

Identify why food is essential for living organisms.

Answer 1

Food is essential for the existence and survival of living organisms as the food provides the energy to the organism to manufacture new cells and therefore sustain life.

Question 2

Describe the role of respiration in obtaining energy from food.

Answer 2

Respiration extracts the energy from the glucose in the food source using the oxygen taken during respiration. This forms energy, carbon dioxide and water.

Question 3

Identify the SI unit for energy

Answer 3

A Joule (J) is the standard SI unit for scientific measurements of energy.

Question 4

Describe what a CARBOHYRDRATE is.

Answer 4

A carbohydrate is any of a large group organic compounds, ranging from glucose, starch and cellulose, found naturally occurring in almost all foods

Question 5

Describe what a PROTEIN is

Answer 5

A protein is an enzyme which produces molecules for cells to use.

Question 6

Describe what a FAT is.

Answer 6

A fat is a storage of excess sugars and energy used by the body later when food is scarce.

Question 7

Describe what a VITAMIN is.

Answer 7

A vitamin is an organic compound required by an organism to sustain life. The vitamin is an organic material(one that contains carbon)

Question 8

Describe what a MINERAL is.

Answer 8

A mineral is an essential element required by organisms to sustain life. A mineral is a non-organic substance (one that does not contain carbon) generally solid, required in trace amounts (other than carbon, hydrogren, nitrogen, oxygen)

Question 9

Identify some common nutrient sources and describe the function of each main nutrient.

Answer 9

Milk: Contains calcium which is essential to bone growth, normal blood clotting and running the nervous system .
Oranges (General citrus fruits): Contains Vitamin C which forms collagen and maintains the health of gums and teeth

Question 10

Describe how plants produce and use carbohydrates as an energy source and synthesise the materials required to grow and repair cells

Answer 10

Plants use a process called photosynthesis, which occurs in the chloroplasts the make glucose using carbon dioxide + water -> glucose + oxygen.
They use this glucose to form new cells using the energy.

Question 11

Identify all the elements in carbohydrates, fats & proteins

Answer 11

Carbon, Hydrogen and Oxygen are the elements in all organic compounds (carbohydrates, fats & proteins)

Question 12

Identify why plants need nutrients obtained from the soil or fertiliser

Answer 12

The plants require nutrients to sustain life.

Question 13

Describe the role of the human digestive system.

Answer 13

The human digestive system is used to absorb nutrients and water for cellular use. This will be provide cells with energy to grow and repair

Question 14

Identify the main organs of the digestive system and describe their function

Answer 14

Mouth: To break down the larger parts of food into smaller parts, and partially digest it using saliva.
Oesophagus: To move food, saliva and liquids to the stomach
Stomach: Where stomach acids, dissolve or break down the chunks of food and prepare them to enter the intestines.
Liver : To process and remove poisons (e.g. Alcohol)
Large intestine: To remove most water and distribute it to the bloodstream
Small Intestine: To remove the nutrients and distribute throughout the blood stream.
Anus: Area where feces are expelled

Question 15

Describe the role of enzymes in digestion

Answer 15

Enzymes function to break down the food consumed in the stomach (IE 1 is the HCl in the stomach)

Question 16

Describe the digestion process between the mouth and the anus.

Answer 16

The mouth takes in the food where it is chewed and partially digested by saliva and it is passed down the oesophagus into the stomach where the stomach acids dissolve the food into manageable substance, which is then passed to the large intestine, where the water is extracted, then the small intestine where the nutrients are extracted. Then the remaining substances are passed through to the rectum where it builds up until it is expelled through the anus

Question 17

Why is the small intestine folded?

Answer 17

The small intestine is folded because it requires a considerable length to process the food but would not be able to fit in a human’s body if stretched out. Therefore it is folded to reduce the space it takes up.

Question 18

What is the equation for respiraton?

Answer 18

oxygen + sugar -> energy + carbon dioxide + water

Question 19

Describe the function and structure of phloem and xylem

Answer 19

Xylem is structured as an tubular shape which allows a continuous column of water and nutrients to transferred to the leaves from the roots.
Phloem is structured as a elongated tube with small sieved tubes in the centre. Phloem moves sugars made during photosynthesis to the rest of the plant.