Photosynthesis Flashcards
(23 cards)
How do plants grow?
By making their own food
What plants can make their own food?
Only green plants because they contain chlorophyll
Plants are:
Autotrophs or producers
Can bacteria do photosynthesis?
Autotrophic bacteria
Yes, however they only contain chlorophyll and not chloroplasts. They need the chlorophyll and other chemicals that are built into their plasma membranes.
What are the two types of bacteria?
- Autotrophs
- Chemosynthetic
What are chemosynthetic bacteria?
It means that they get their energy they need from chemical reactions between inorganic molecules.
where does photosynthesis take place?
In plant cells with chloroplasts mainly in the leaves.
What is the structure of the leaf?
- Leaves are flat and wide to create and large surface area.
- Leaves are thin so gasses can reach cells easily.
- Leaves have lots of veins to carry water to cells and glucose away.
- Leaves have holes called stomata. They allows gases in and out.
What does chlorophyll do?
It absorbs the energy from the sunlight that allows carbon dioxide and water to react.
What is inside a chloroplast?
- Stroma: A liquid interior or matrix full of enzymes.
- Thylakoid membranes: flat, sac-like structures grouped together into stacks called GRANA. They contain the chlorophyll.
What are pigments?
- They are substance that absorb visible light.
What are the two types of pigments?
- Chlorophyll A (The main photosynthetic pigment)
- Chlorophyll B (an accessory pigment)
What is photosynthesis?
It is a chemical reaction that absorbs light energy to change carbon dioxide and water into glucose and the by-product oxygen and water.
What is the photosynthesis formula?
6CO2 + 12H2O –> C6 H12 O6 + 6O2 + 6H2O
How does water enter a plant?
Water from the soil enters a plant through the roots .
Why are roots branched and spread out?
- to absorb water (and mineral salts) from a large amount of soil.
- to anchor the plant in the soil.
Why is water important?
- To provide dissolved minerals that keep plants healthy.
- to transport substances
- to keep the plant rigid and upright.
- to keep the plant cool
- To allow chemical reactions to occur.
Why do plants need glucose?
- Some glucose is used in cellular respiration.
- Some is converted into starch for storage .
- Some is used to make new chemicals such as proteins, sugars and fats.
What are the two types of reactions in photosynthesis?
- Light Dependent Reactions (Requires sunlight).
2. Light Independent Phase or Dark reactions. (Occurs without sunlight).
Light Dependent Reactions:
- It occurs in the Grana.
- It spilts water
- releases oxygen
- produces ATP to form NADPH.
Light Independent Phase or Dark reactions.
- Also known as the Calvin Cycle
- It occurs in the Stroma
- It forms sugar from carbon dioxide
- It uses ATP for energy
- It uses NADPH for reducing power.
What limits photosynthesis?
- the amount of light
- carbon dioxide levels
- temperature
- amount of water
- pollution
Summary:
- Light energy is trapped by the chlorophyll and it is used to split water molecules into hydrogen and oxygen.
- The hydrogen then combines with carbon dioxide molecules to make glucose, water and the oxygen is released into the atmosphere as a ‘waste’ product.
