Respiration And Photosythesis Year 10 Flashcards
Equation for photosynthesis (words)
Carbon dioxide + water —> glucose + oxygen
Light energy
Chlorophyll
Equation for photosynthesis (formula)
6CO2 + 6H2O —> C6H12O6 + 6O2
What happens to Carbon Dioxide during photosynthesis
Carbon dioxide diffuses in from the air through the stomata of the leaf
What happens to water during photosynthesis
Water from the soil absorbed by the root hair cells (large SA) by osmosis
What happens to glucose during photosynthesis
Used in respiration (releases energy) converted into starch. Used to produce fat - or oil for storage, cellulose to strengthen cell walls and provide protein
What happens to oxygen during photosynthesis
Some used in respiration net production of oxygen
Oxygen diffused out of leaf through stomata
Why does a leaf have a flat, thin, large surface area
To absorb maximum light energy
Thin so gases (CO2) can diffuse to the palisade cells quickly and easily
Why does a leaf contain chlorophyll
To absorb light for photosynthesis
Why do leaves have a network of veins
To transport water and minerals to the leaf (xylem) and carbohydrates away from the leaf (phloem)
Why do leaves have a waxy layer
Waxy layer and upper epidermis are translucent to allow light to pass through to the palisade cells
What you can you do to test if photosynthesis has taken place
Leaves can be tested for starch by using iodine
Turns from yellow to blue black
The inverse square law
Light is proportional to 1/distance (d) ^2
Factors limiting the rate of photosynthesis
Carbon dioxide, as levels increase so does the rate of photosynthesis
Temperature, as temp increases, so does rate until 45*C
Light intensity
Hydroponics
Artificial growing system that uses water instead of soil, the roots are given minerals in a controlled manner
Crops sold to supermarkets
Advantages of hydroponics
5 times the yield compared to growing on a field
No need for weed killers or pest killers
Less harmful to environment (eutrophication)
Can monitor and manipulate O2 and minerals
Disadvantages of hydroponics
More workers so more costly
Computers and monitoring systems can be costly
Expensive to start up business
Small holding
Small area of land where different crops grown
Beans always grown because they contain nitrate (leguminous) needed for other plants to grow
Every year plants rotated and planted in place of crop before so they all get nutrients needed to grow
Arable farming
Farms crops (wheat and oil seed rape) in area of large land After harvest, stubble plunged back into ground Fertiliser is added to keep mineral levels right
What is respiration
Releasing energy from food
Equation for aerobic respiration (word)
Oxygen + glucose —> Carbon Dioxide + water (+energy)
Equation for aerobic respiration (formula)
6O2 + C6H12O6 —> 6CO2 + 6H2O
What is aerobic respiration and where does it take place
Takes place in every living cell or specialised membranes
Enzyme controlled reaction
Reaction transfers energy from glucose into energy (exothermic)
What are the membranes in eukaryotes and prokaryotes involved in aerobic respiration
Eukaryotes- the membranes are in the mitochondria
Prokaryotes- the membranes are called mesosomes
Oxygen in aerobic respiration
Breathed in through lungs —> blood —> circulates, diffuses into all cells
Glucose in aerobic respiration
Digested into digestive system —> absorbed into blood —> diffuses into cells
Carbon dioxide in aerobic respiration
Produced by respiration in cells, diffuses into blood then carried around body to alveoli, then diffuses into lungs and breathed out
Water in aerobic respiration
Produced by cells in respiration, diffuses out into blood by osmosis, circulates around body then excess removed through sweat, urine and breath
Use of energy in aerobic respiration
Used for contraction of muscles, active transport, chemical reactions within cells, cell division and protein synthesis
Role of cytoplasm in aerobic respiration
Where enzymes are made, locations of reactions in aerobic respiration
Role of nucleus in aerobic respiration
Holds genetic code for enzymes involved in respiration
Role of mitochondria in aerobic respiration
Contains enzymes for aerobic respiration
Roll of cell membrane in aerobic respiration
Allows gases and water to pass freely into and out of cell. Controls passage of other molecules
What are mitochondria
Small rod shaped organelles found in most eukaryotic cells.
Folded inner membrane-large surface area for enzymes involved in aerobic respiration
What does the number of mitochondria in a cell show
How active the cell is
muscles
Use of lost of energy for movement, support, breathing and circulation
Muscle tissue made of protein fibres that occur in big blocks or groups called muscles
Contract to cause movement, relax when role is finished
Effect of exercise on muscles
Contract using energy from respiration
Contain many mitochondria
Contain glycogen stores
What is glycogen
Carbohydrate that is rapidly hydrolysed into glucose
Change of heart and lung functions during exercise
Increase in heart rate, breathing rate and breath volume
Glycogen stores in muscles converted to glucose for cellular respiration
Flow of oxygenated blood to muscles increases
What’s the function of glycogen
The store of energy that can be converted back to glucose to be used for cellular respiration
Why do muscles contain a store of glycogen when most other body tissues don’t?
Normal cells get glucose form diffusion and muscles work hardest so need a store of glycogen for contraction
What is anaerobic respiration
Respiration without oxygen
During vigorous exercise cells become short of oxygen because not supplied fast enough bust energy can still be obtained through glucose but without the oxygen
Equation for anaerobic respiration
Glucose —> lactic acid + energy (small amounts)
Muscle fatigue
Muscle fibres become fatigued after carrying out long exercise
Stop contracting efficiently
Very short of oxygen so switch to anaerobic respiration
Efficiency of anaerobic respiration
Not as efficient
Less energy is released than during aerobic respiration
Without oxygen, the break down of glucose molecule is incomplete
Oxygen debt
After exercise heart and breathing rate remain high
Length of time out of breath depends on fitness
Lactic acid can’t be breathed out
Lactic acid has to be broken down needing oxygen. Known as oxygen debt
Equation for oxygen debt
Lactic acid + oxygen —> Carbon Dioxide + water
Role of liver in breakdown of lactic acid
As lactic acid accumulates in muscle cells, it enter bloodstream. Liver soaks up circulating lactate, when resting, liver is busy oxidising lactic acid into carbon dioxide and water
How do the arteries supplying the leg muscle alter the rate of blood flow through them during exercise
The arteries dilate to allow more blood flow
How does an increase in heart rate help a student during exercise
Muscles use more energy and more energy is released
Muscles respire faster and supply more oxygen and glucose
They remove CO2 lactic acid and heat to cool the muscle cells
What is metabolism
Sum of all reactions in a cell or the body
Energy transferred by respiration in cells is used by the organism for the continual enzyme controlled process of metabolism that synthesise new molecules
Types of metabolism
There are hundreds of chemical reactions taking place in our body at any one time
