Topic 6 Flashcards
Photosynthesis equation
WORD
Carbon dioxide + water ➡️ oxygen + glucose
Photosynthesis equation
SYMBOL
6CO2 + 6H2O ➡️ 602 + C6H12O6
666
What is photosynthesis
A chemical reaction in which the products ( glucose & oxygen) have more energy than the reactants (carbon dioxide & water)
ENDOTHERMIC REACTION - TAKES IN ENERGY
How do plants absorb sunlight
Using chlorophyll found in the chloroplast of their leaves
Limiting factors
Temperature
Carbon dioxide
Light intensity
Effect of temperature
As it increase the rate of photosynthesis increases until it reaches its optimum and then decreases again-denature
How does temperature effect the rate of reaction
It increase the rate if chemical reactions because the particles have more kinetic energy
When the optimum temperature is reached the active site changes and it denatures causing the rate to decrease
Effect of carbon dioxide concentration
As it increases so does the concentration until it reaches a maximum rate
How does carbon dioxide concentration effect the rate of reaction
It increase because carbon dioxide is a raw material needed in photosynthesis the rate increase until another factor begins to limit the rate such as amount of chlorophyll
Effect of light intensity
without light a plant cannot grow it allows photosynthesis to occur until a maximum rate when a another factor begins to limit
Diffusion definition
The PASSIVE movement of molecules from an area of HIGH concentration to an area of LOW concentration ( down the concentration gradient)
No energy required
Osmosis definition
PASSIVE movement of WATER molecules from an area of HIGH concentration to an area of LOW concentration ( down the concentration gradient)
Through a partially permeable membrane
Active transport definition
Movement of molecules from an area of LOW concentration to an area of HIGH concentration ( against the concentration gradient)
Requires ENERGY from respiration
How is water lost from plants
Through the leave surface area -known as transpiration
How does water enter the plant
Through the root hair cells in the roots
Adaptations of a root hair cell
Long finger like end- to increase the surface area and allow more minerals to be reached for the plant
Hairs along the surface to increase the surface area
Absorb water and dissolved minerals mor effectively
No chloroplast - no light = no photosynthesis
Adaptations of the xylem
- thick walls containing lignin- provide support for the plant BUT causes the xylem to die
- no nucleus,cytoplasms,vacuole or chloroplast makes it easier for water and minerals to flow through
- tiny pores allow water and mineral ions to enter and leave the xylem
- lack of cells between the cells means water flow isn’t slowed down
Function of the phloem
Carries dissolved sugars up and down the plant (taken to growing tissue)
Adaptations of the phloem
No nucleus and limited cytoplasm
Sieve plates
What are the companion cells in the phloem
Mitochondria in them provide energy to the phloem vessel cell
Order of translocation
1) Starch is made by photosynthesis in chloroplast
2) Starch is broken down when it’s dark, products of breakdown are moved into the cytoplasm of the cells
3) Products of starch are used to mask sucrose (soluble sugar)
4) Sucrose is moved via active transport into the companion cells
5) Together the companion and sieve cells form the PHLOEM. The pumping of sucrose into sieve cells causes a pressure difference, which causes the contents to move either up or down
Adaptations of the companion cells and sieve cells
USED IN TRANSLOCATION
1) Companion cells have many mitochondria, release energy. Have small pores between the and sieve cells, pump sucrose into sieve cells
2) Sieve cells have no nucleus and small amounts if cytoplasm in order to make the central channel wide for easy flow of liquids
Adaptation of leaves for gas exchange
Cells in the spongy mesophyll are loosley packed and covered by a thin film of water
Tiny pores called STOMATA, in the surface area of the leaf
Role of the stomata
Controls gas exchange in the leaf
Can be opened or closed in how turgid the guard cells are
