Food and Digestion Notes

Alimentary Canal and Digestion

  • May/2021/Paper_1/No.1

    • (a) Location of acid addition in the alimentary canal:

      • Correct answer: C (Stomach)

    • (b) Location of digested food absorption into the blood:

      • Correct answer: E (Small intestine)

    • (c) Part A connects:

      • Mouth
      • Esophagus

Food Webs

  • Nov/2020/Paper_1/No.4

    • (a) Animals eaten by the wild cat:

      • Rabbit
      • Vole

    • (b) Complete food chain including goat:

      • Grass -> Goat -> Jackal

    • (c) Effect of decreasing voles on rabbits:

      • Rabbits may increase because wild cats might switch to eating more rabbits if voles decrease.

    • (d) Ways energy is lost from food webs:

      • Heat loss, excretion, undigested materials

Enzyme Digestion and pH

  • May/2020/Paper_1/No.10

    • (a) (i) pH with the shortest digestion time:

      • pH 2

    • (a) (ii) Steps to ensure accuracy in finding the shortest time:

      • Repeat the experiment multiple times at each pH.
      • Use smaller pH intervals around the suspected optimal pH.

    • (b) (i) Safety risk of using very low pH liquids:

      • Chemical burns/Irritation.

    • (b) (ii) Way of reducing the safety risk:

      • Wear gloves and eye protection.

    • (c) Variable to control in the investigation:

      • Temperature, enzyme concentration, volume of egg white.

Human Stomach Structure and Function

  • Nov/2019/Paper_1/No.1

    • (a) Term that best describes the stomach:

      • Organ

    • Explanation: The stomach is made of different tissues working together (muscles, blood vessels, digestive cells).

    • (b) (i) Red blood cell structure and function:

      • Red blood cells have a biconcave shape for a large surface area and contain hemoglobin to transport oxygen efficiently.

    • (b) (ii) Muscle cell structure and function:

      • Muscle cells are elongated and contain protein filaments (actin and myosin) that slide past each other, enabling contraction and movement.

Diet and Exercise for Athletes

  • May/2018/Paper_2/No.1

    • (a) (i) Main nutrient in chicken:

      • Protein

    • (a) (ii) How protein improves strength:

      • Protein is used to repair and build muscle tissue, increasing muscle mass and strength.

    • (b) Importance of starchy foods (pasta) before a rugby game:

      • Starchy foods provide carbohydrates, which are broken down into glucose to provide energy for the strenuous activity.

Healthy Balanced Diet

  • Nov/2017/Paper_2/No.1

    • (a) (i) Nutrients provided by cereals and whole grains:

      • Carbohydrates

    • (a) (ii) Why we need these nutrients:

      • Carbohydrates are the body's primary source of energy.

    • (b) Nutrients that help prevent deficiency diseases like scurvy and rickets:

      • Vitamins

    • (c) Harmful result of eating too much fat and oil:

      • Weight gain, heart disease, increased cholesterol levels.