Nutrition and Digestion
Life Science
Nutrition in Animals
The Need for Food
All animals need nutrition, food provides energy for plants, animals.
Autotroph: Organism that can make its own food using light, water, carbon dioxide, other chemicals.
Heterotroph: Organisms that eat other plants, animals for energy and nutrients.
Plants can produce their own food. Animals can’t need to eat other animals, plants.
The Need for Digestion
Foods animals eat consist large insoluble molecules.
Molecule broken into smaller soluble molecule=
digestion.
These molecules able pass into cell membranes of
cells.
Unicellular Animals:
- E.g., Amoeba get food from environment. The
food passes into cells by diffusion.
- Diffusion: Molecules move from a high
concentration to a low concentration.
- Amoeba takes food in (Ingestion, digests it (Digestion), gets rid of waste (Egestion).
- Digestion takes place in cell, called intracellular digestion.
- Special molecules called enzymes can break down the smaller molecules.
Multicellular animals:
- Need complex system to get food to cells. Need diff ways taking food in, digesting it, getting rid of it.
- Digestion takes place outside cell, called extracellular digestion.
Human Nutrition
Balanced Diet
We must eat balanced diet to lead healthy life.
Provides enough energy right amount each diet
components.
Sun is original of all energy; plants use it for
photosynthesis to make food. Carbohydrates (Sugar),
Oxygen end product.
Carbohydrates=energy rich molecules consisting of 3
elements C, H, O.
Humans, animals depend on plants for food. This
energy used for everyday activities.
Food classified in groups. Need right amount of each
group to ensure body functions properly.
,Food Groups
Type Function Source
Carbohydrates Gives body energy Sugars, starches
Proteins Builds and repairs cells Meat, fish, poultry, eggs, beans, dairy
Fats Stores energy and helps build cells Oils, nuts, butter, meat, full cream
dairy
Fibre Helps with digestion Corn, fruit, vegetables, bread
Minerals Iron: Good for blood. Liver, kidney, eggs meat, dried fruit
Calcium: Builds strong teeth, bones Dairy Products
Magnesium: Good nervous system Fresh fruit, fish, meat
Iodine: Controls rate at which energy Milk, seafood, green vegetables
is released from food
Sodium Chloride: Helps digestion, Fresh fruit, vegetables, meat, milk
nerves work.
Vitamins A: Protects epithelial tissue Liver, kidneys, eggs, milk, fish liver oils
B12: Help make new red blood cells Milk, liver, meat, eggs fish.
C: Help heal wounds, protect against Citrus fruits, green vegetables, peas.
diseases.
D: Absorbs calcium Liver, fish, sunlight
K: Helps with blood clotting Dark green leafy vegetables
Water
Water is vital for life.
70% of your body= water. About half the water you take comes from food.
Person can survive many days without food. Only 2 days without water.
Need 6-8 glasses water every day.
Potatoes= 75% water. Milk” 87% water. Cucumber= 98% water. Cheese=28% water.
Functions of water:
- Serves as medium in which chemical reactions can take place.
- Serves as mean of transport for nutrients.
- Also transports undigested, unabsorbed food/leftovers, waste.
- Serves as lubricant.
- Serves as a solvent.
- Helps with thermoregulation.
Thermoregulation: Regulation of body temp make sure body temp is 37°C. Body cell only able function this temp.
- If too hot, you sweat to cool down. Organs can overheat, denature. Hyperthermia.
- If too cold, shiver to warm up. Body can denature. Hypothermia.
- Denature: When body cells stop functioning
Connection Between Food and Exercise
Your body uses energy in food you eat to function, preform bodily activities.
Exercise important for general health:
- Increases metabolism.
- Controls blood circulation prevents heart disease.
- Controls body mass.
- Improves muscle tone and skeletal muscle posture.
- Helps prevent osteoporosis.
Osteoporosis: a medical condition in which the bones become brittle and fragile from loss of tissue.
Juvenile osteoporosis: Found in younger people.
, Diet Disorders
Malnutrition
Means bad feeling. In other words, people don’t eat enough of 1/ more food group.
This can lead to overeating, under eating, also not eating food in correct proportion.
Overeating can lead to obesity. Excess food stored as fat. Too much fat= bad for health
When people under eat their energy reserves will be used up, their bodies will start wasting away.
Deficiency Diseases
Disease Symptoms Cause
Rickets (Rachitis) Deformed, bending of bones, bones Lack of Vit D
are soft.
Scurvy Bleeding gums, under skin Lack of Vit C
Night Blindness Poor night vision Lack of Vit A
Goitre Swelling of thyroid gland Lack of Iodine
Anaemia Tiredness and weakness Lack of Iron
Pellagra Skin rashes Lack of Vit B
Dietary Diseases
Disease Symptoms Cause
Marasmus Wasting away of muscles, body Diet low in kilojoules, proteins.
becomes thin, weak General starvation.
Anorexia Nervosa Loss of weight, wasting away. Sterility
Psychological condition when person
refuses to eat.
Bulimia Nervosa Excessive waste loss Psychological condition where person
over eats, vomits after eating.
Obesity Body mass increases. High blood Overeating.
pressure, heart disease, diabetes
Kwashiorkor Bloated belly, blubbery cheeks Too little protein in diet.
Life Science
Nutrition in Animals
The Need for Food
All animals need nutrition, food provides energy for plants, animals.
Autotroph: Organism that can make its own food using light, water, carbon dioxide, other chemicals.
Heterotroph: Organisms that eat other plants, animals for energy and nutrients.
Plants can produce their own food. Animals can’t need to eat other animals, plants.
The Need for Digestion
Foods animals eat consist large insoluble molecules.
Molecule broken into smaller soluble molecule=
digestion.
These molecules able pass into cell membranes of
cells.
Unicellular Animals:
- E.g., Amoeba get food from environment. The
food passes into cells by diffusion.
- Diffusion: Molecules move from a high
concentration to a low concentration.
- Amoeba takes food in (Ingestion, digests it (Digestion), gets rid of waste (Egestion).
- Digestion takes place in cell, called intracellular digestion.
- Special molecules called enzymes can break down the smaller molecules.
Multicellular animals:
- Need complex system to get food to cells. Need diff ways taking food in, digesting it, getting rid of it.
- Digestion takes place outside cell, called extracellular digestion.
Human Nutrition
Balanced Diet
We must eat balanced diet to lead healthy life.
Provides enough energy right amount each diet
components.
Sun is original of all energy; plants use it for
photosynthesis to make food. Carbohydrates (Sugar),
Oxygen end product.
Carbohydrates=energy rich molecules consisting of 3
elements C, H, O.
Humans, animals depend on plants for food. This
energy used for everyday activities.
Food classified in groups. Need right amount of each
group to ensure body functions properly.
,Food Groups
Type Function Source
Carbohydrates Gives body energy Sugars, starches
Proteins Builds and repairs cells Meat, fish, poultry, eggs, beans, dairy
Fats Stores energy and helps build cells Oils, nuts, butter, meat, full cream
dairy
Fibre Helps with digestion Corn, fruit, vegetables, bread
Minerals Iron: Good for blood. Liver, kidney, eggs meat, dried fruit
Calcium: Builds strong teeth, bones Dairy Products
Magnesium: Good nervous system Fresh fruit, fish, meat
Iodine: Controls rate at which energy Milk, seafood, green vegetables
is released from food
Sodium Chloride: Helps digestion, Fresh fruit, vegetables, meat, milk
nerves work.
Vitamins A: Protects epithelial tissue Liver, kidneys, eggs, milk, fish liver oils
B12: Help make new red blood cells Milk, liver, meat, eggs fish.
C: Help heal wounds, protect against Citrus fruits, green vegetables, peas.
diseases.
D: Absorbs calcium Liver, fish, sunlight
K: Helps with blood clotting Dark green leafy vegetables
Water
Water is vital for life.
70% of your body= water. About half the water you take comes from food.
Person can survive many days without food. Only 2 days without water.
Need 6-8 glasses water every day.
Potatoes= 75% water. Milk” 87% water. Cucumber= 98% water. Cheese=28% water.
Functions of water:
- Serves as medium in which chemical reactions can take place.
- Serves as mean of transport for nutrients.
- Also transports undigested, unabsorbed food/leftovers, waste.
- Serves as lubricant.
- Serves as a solvent.
- Helps with thermoregulation.
Thermoregulation: Regulation of body temp make sure body temp is 37°C. Body cell only able function this temp.
- If too hot, you sweat to cool down. Organs can overheat, denature. Hyperthermia.
- If too cold, shiver to warm up. Body can denature. Hypothermia.
- Denature: When body cells stop functioning
Connection Between Food and Exercise
Your body uses energy in food you eat to function, preform bodily activities.
Exercise important for general health:
- Increases metabolism.
- Controls blood circulation prevents heart disease.
- Controls body mass.
- Improves muscle tone and skeletal muscle posture.
- Helps prevent osteoporosis.
Osteoporosis: a medical condition in which the bones become brittle and fragile from loss of tissue.
Juvenile osteoporosis: Found in younger people.
, Diet Disorders
Malnutrition
Means bad feeling. In other words, people don’t eat enough of 1/ more food group.
This can lead to overeating, under eating, also not eating food in correct proportion.
Overeating can lead to obesity. Excess food stored as fat. Too much fat= bad for health
When people under eat their energy reserves will be used up, their bodies will start wasting away.
Deficiency Diseases
Disease Symptoms Cause
Rickets (Rachitis) Deformed, bending of bones, bones Lack of Vit D
are soft.
Scurvy Bleeding gums, under skin Lack of Vit C
Night Blindness Poor night vision Lack of Vit A
Goitre Swelling of thyroid gland Lack of Iodine
Anaemia Tiredness and weakness Lack of Iron
Pellagra Skin rashes Lack of Vit B
Dietary Diseases
Disease Symptoms Cause
Marasmus Wasting away of muscles, body Diet low in kilojoules, proteins.
becomes thin, weak General starvation.
Anorexia Nervosa Loss of weight, wasting away. Sterility
Psychological condition when person
refuses to eat.
Bulimia Nervosa Excessive waste loss Psychological condition where person
over eats, vomits after eating.
Obesity Body mass increases. High blood Overeating.
pressure, heart disease, diabetes
Kwashiorkor Bloated belly, blubbery cheeks Too little protein in diet.
