Nutrition Flashcards
What is photosynthesis?
Photosynthesis is the process where some organisms are able to turn light energy into chemical energy.
What type of organisms use photosynthesis to make their own food?
Producers
What type of reaction is photosynthesis?
Photosynthesis is an endothermic reaction.
Where does photosynthesis take place?
Photosynthesis takes place in the chloroplasts.
What is the word equation for photosynthesis?
Carbon dioxide + Water → Glucose + Oxygen
What is the symbol equation for photosynthesis?
Explain the effect of temperature on the rate of photosynthesis
- As temperature increases, so does the rate of photosynthesis
- Once the temperature exceeds the optimum, the rate of photosynthesis decreases as enzymes begin to denature
Explain the effect of light intensity on the rate of photosynthesis
As the light intensity increases, so does the rate of photosynthesis.
What is the inverse square law?
As the distance from the light source
doubles, the light intensity quarters.
Explain the effect of carbon dioxide concentration on the rate of photosynthesis
As the concentration of carbon dioxide increases, so does the rate of photosynthesis.
What is a limiting factor?
A factor that limits the rate of a reaction when there is not enough of it.
Describe the structure of leaf tissue
Give 3 ways leaves are adapted for photosynthesis
- They are thin which provides a short diffusion distance
- The spongy mesophyll layer has lots of air spaces for efficient gas exchange
- Palisade mesophyll cells have lots of chloroplasts for photosynthesis
What are mineral ions used for in a plant?
Mineral ions are used for growth in plants.
Give 2 common ions in plants
What are magnesium ions used for in plants?
They are used in chlorophyll
What are nitrate ions used for in organisms?
Nitrate ions are used in amino acids.
Why is a balanced diet important?
The body needs different substances in different proportions to function properly, too much or too little of different things can be harmful.
What 7 groups are needed for a balanced diet?
- Carbohydrates,
- proteins,
- lipids (fats),
- vitamins,
- minerals,
- water
- dietary fibre.
What is the function of carbohydrates in the diet?
Carbohydrates are the body’s main source of energy.
What are the functions of proteins in the body?
Proteins can have structural or metabolic roles in the body and are used as hormones, enzymes, antibodies, etc
What are the functions of lipids in the body?
- Energy storage
- Cell membranes
- Buoyancy
- Insulation
What is vitamin A used for?
- Keeping the skin healthy
- Improved vision in the dark
- Strengthening the immune system
What is vitamin C used for?
Growth and repair
What is vitamin D used for?
Vitamin D is used in the absorption of calcium.
What is calcium used for in the body?
Calcium strengthens bones and teeth.
What is iron used for in the body?
Iron is used in haemoglobin to transport oxygen in the blood.
What is water used for in the body?
- A reaction medium
- Temperature control
- Transport
What is dietary fibre used for?
It helps keep everything flowing through the digestive system.
Compare the energy requirements of more and less active people
The more active a person is, the greater their energy requirement.
Describe how energy requirements change as we age
Adults generally require more energy than children.
What is the alimentary canal?
The alimentary canal is the complete tube that food passes through as it passes through the body.
What is the difference between the alimentary canal and the digestive system?
The alimentary canal involves the tubes that the food passes through whereas the digestive system also includes digestive glands.
Describe the passage of food through the alimentary canal
Mouth → oesophagus → stomach → small intestine → large intestine → rectum
What is the function of the mouth?
- To chew and break down food
- To secrete digestive enzymes
What is the oesophagus?
The tube that carries food from the mouth to the stomach.
What does the stomach do?
The stomach is a muscular sac containing acid that pummels the food and breaks it down further.
What role does the pancreas play in digestion?
The pancreas secretes digestive enzymes into the small intestine.
What are the two parts of the small intestine called?
Duodenum and ileum
What is the function of the duodenum?
The duodenum receives food directly from the stomach and uses enzymes and chemical digestion to break the food down.
What is the function of the ileum?
Most nutrients are absorbed from the food in the ileum into the blood.
How is the ileum adapted for absorption?
The ileum is lined with villi which provide a large surface area for reabsorption
How are villi adapted for absorption?
- Thin walls
- Large surface area
- Good blood supply close to the surface
What is the function of the large intestine (colon)?
Water is reabsorbed into the blood in the large intestine
What is the function of the rectum?
The rectum stores faeces before egestion
How does peristalsis work to push food through the gut?
Muscles contract in a wave like fashion which pushes food along.
What enzymes break starch down to glucose?
Maltase and amylase
What group of enzymes break proteins down into amino acids?
Proteases
What group of enzymes break lipids down into glycerol and fatty acids?
Lipases
What does bile do?
- Bile neutralises the stomach acid and provides alkaline conditions for the digestive enzymes in the small intestine
- Bile also emulsifies fats
Where is bile produced?
Bile is produced in the liver
Where is bile produced?
Bile is produced in the liver
Where is bile stored?
Bile is stored in the gallbladder
