2E 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?
Endothermic reaction
Where does photosynthesis take place?
In the chloroplasts
Word equation for photosynthesis
Carbon dioxide + water –> glucose + oxygen
Symbol equation for photosynthesis
6CO2 + 6H2O –> C6H12O6 + 6O2
Explain the effect of temperature on the rate of photsyntesis
- As temperature increases, so does the rate of photosynthesis
- When it exceed the OPTIMUM TEMP, the RATE of photosynthesis DECREASES as enzymes begin to DENATURE
Explain the effect of light intensity on the rate of photosynthesis
As light intensity increases, rate of photosynthesis increases
Explain the effect of carbon dioxide concentration on the rate of photosynthesis
As the CO2 concentration increases, the rate of photosynthesis also increases
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
- Waxy Cuticle
- Upper Epidermis
- Palisade Mesophyll
- Spongy Mesophyll
- air spaces
- Lower Epidermis
- Guard Cells / Stomata
Upper epidermis
- To prevent water loss
- To protect the leaf
Palisade Mesophyll
contains palisdade cells that contain chlorophyll to make PHOTOSYNTHESIS
Spongy Mesophyll
contains air spaces to let gases diffuse into the cells
Guard cell
- allows carbon dioxide into leaf
- controls the size of the stomata
Xylem
- Transports WATER and MINERALS from the roots to the leaf
- Strength
Phloem
- Transports SUCROSE and AMINO ACIDS from leaves to other parts of plant
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 photsynthesis
What are mineral ions used for in a plant?
Mineral ions are used for growth in plants
2 Common ions in plants
Magnesium ion (Mg2+)
Nitrate ion (NO2-)
What are magnesium ions used for in plants?
needed to make chlorophyll
What are nitrate ions used for in organisms?
to make amino acids (to build proteins)
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 are 7 groups needed for a balanced diet
- Carbohydrates
- Proteins
- Lipids (fats)
- Vitamins
- Minerals
- Water
- Dietary fibre
Function of carbohydrates in the diet
Carbohydrates are the body’s main source of energy
Function of proteins in the body
Proteins are used for growth and repair body’s tissues
Funtions of lipids in the body
- Energy storage
- Cell membranes
- Insulation
What is vitamin A used for
- keepin the skin healthy
- improved vision in the dark
- strengthening the immune system
What is vitamin C used for
sticks together cells linning surfaces
What is vitamin D used for
used in the absorption of calcium + phosphate
What is calcium used for in the body
strenghthens teeth and bones
What is iron used for in the body
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?
helps to keep everything flowing through the digestive system
Energy requirements in different people
The more active the person is, the greater their energy requirement.
Describe how energy requirements change as we age
Adults generally require more energy than children
Passage of food through 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 amylase 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 HCl that pummels the food and breaks it down further
- Secretes protease enzymes
What role does the pancreas play in digestion
The pancreas secretes amylase, protease and lipase 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 down food
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
- Microvilli
- 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 peristalisis work to push food through the gut?
- Contraction of circular muscles behind the food, narrows the gut, pushing the food along.
- When the circular muscles contrat
- the longitudinal muscles relax..
What enzymes break starch down to maltose?
Amylase
What enzymes break maltose down to glucose?
Maltase
What group of enzymes break proteins down into amino acids?
Proteases
What group of enzmes break lipids down into glycerol and fatty acids
Lipases
What does bile do?
1- Bile neutralises the stomach acid
-providing alkaline conditions
- for the digestive enzymes in the small intestine
2- Bile also emulsifies fats
Where is bile produced
Bile is produced in the liver
Where is bile stored
Bile is stored in the gallbladder
Leaf adaptations (TCLWVCM)
-Thin (to allow gases to diffuse easily)
-Can change direction (to face the sunlight)
-Large surface area (to absorb more light)
-Waxy layer on top of the leaf (to reduce water loss)
-Chloroplasts (contain chlorophyll that absorbs light energy from the sun)
-Veins (to transport water to the leaf and glucose away from the leaf)
-Many stomata ( to allow gas exchange)
