2E Nutrition Flashcards
Write the word equation for photosynthesis
Carbon dioxide + water → glucose + oxygen
Write the symbol equation for photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
What are the reactants of photosynthesis
Carbon dioxide
Water
What are the products of photosynthesis
Glucose
Oxygen
What energy conversion takes place during photosynthesis
Light → Chemical
Describe how 3 factors that affect the rate of photosynthesis
Increased temperature = increased rate (enzymes have more kinetic energy)
Increased light intensity = increased rate
Increased CO2 concentration = increased rate
Describe the function of the waxy cuticle of a leaf
Waterproof layer
Prevents water loss by evaporation
Prevents disease entry
Describe the function of the upper epidermis of a leaf
Transparent cells allow light to pass through to reach palisade cells for photosynthesis
Describe the function of palisade mesophyll of a leaf
Has many chloroplasts for photosynthesis
Tightly packed together to increase surface area for absorbing sunlight
Describe the function of spongy mesophyll of a leaf
Has many air spaces for diffusion of carbon dioxide and oxygen for gas exchange
Describe the function of guard cells/stomata of a leaf
Open and close to allow diffusion of carbon dioxide in and oxygen out
Allows transpiration of water
Guard cells become turgid or flaccid to control opening of stomata
Describe the function of two mineral ions found in soil and used by plants
Magnesium ions (Mg2+) = make chlorophyll for photosynthesis
Nitrate ions (NO3-) = make amino acids for growth
Describe how to test a leaf for starch
Add a leaf to boiling water to soften cell walls of leaf
Add the leaf to boiling ethanol to dissolve and remove chlorophyll (careful - ethanol is flammable)
Add iodine to the leaf → turns blue/black if starch present
Describe what is meant by a variegated leaf
A leaf that contains areas with chlorophyll and no chlorophyll
Explain why counting bubbles is an inaccurate way to measure the rate of photosynthesis of pondweed
Bubbles have different sizes
Bubbles can be too fast to count or too small to see
Describe what is meant by a balanced diet
The correct proportion of all the major food groups
Name the 7 key food groups required for a balanced diet
Proteins
Carbohydrates
Lipids
Fibre
Water
Vitamins
Minerals
Give a source of, and function of, carbohydrates
Rice, bread, potatoes
Used in respiration to release energy
Give a source of, and function of, proteins
Meat, fish, nuts, eggs
For growth and repair
Give a source of, and function of, lipids
Cheese, butter, oils
For insulation, energy storage, buoyancy
Give a source of, and function of, vitamin A
Carrots
Helps with vision
Lack of it leads to night blindness
Give a source of, and function of, vitamin C
Citrus fruits e.g. oranges
Helps with infections and wound healing
Lack of it leads to scurvy
Give a source of, and function of, vitamin D
Sunlight
Helps with bone growth
Lack of it leads to rickets
Give a source of, and function of, calcium
Milk
Helps with bone growth
Lack of it leads to brittle bones and tooth damage
Give a source of, and function of, iron
Red meat
Iron important for making haemoglobin
Lack of it leads to anaemia (less oxygen transported in blood)
Give a source of, and function of, water
Fruits e.g. watermelons
Important for hydration of cells
Give a source of, and function of, fibre
Beans, vegetables, whole grains
Helps bowel movement
Lack of it leads to constipation
Define the term metabolism
All of the chemical reactions occurring in the body
Describe the link between energy requirement and your activity level
Increased activity level = increased metabolic rate
Describe the link between energy requirement and age
Increased age = decreased metabolic rate
Describe the link between energy requirement and pregnancy
Pregnancy = increased metabolic rate
Describe the function of the mouth in digestion
Mechanical digestion - break down food into smaller pieces (increase surface area)
Amylase in saliva breaks down starch into maltose
Describe the function of the oesophagus in digestion
Transports the bolus (food from mouth) from mouth to stomach
Describe the function of the stomach in digestion
Mechanical digestion - muscles contract to churn food
Chemical digestion - hydrochloric acid and protease enzymes break down proteins
