Photosynthesis

Photosynthesis...

• - Photosynthesis is the process occurring in green plants which
• transforms carbon dioxide and water into glucose and oxygen using sunlight.
• Energy is stored in the forms of glucose, starch and cellulose
• - Glucose is then used for respiration
• PRODUCTS...
• - Glucose - used as fuel for respiration
• - Starch - is stored in starch granules
• - Cellulose - for forming cell walls
• BY-PRODUCTS...
• - Oxygen gas
• - Released into the atmosphere
• - Used by animals for breathing
• - Maintains the atmospheric CO2/ O2 ratio at a constant level

Photosynthesis continued...

• CO2 - enters from the air through stomata
• H2O - from the cell sap (originally from the soil)
• Sunlight - red and blue
• wavelengths
• Enzymes - to control the
• reactions
• 
• Caption: Photosynthesis Equation...

Photosynthesis factors...

• 
• - Light Intensity
• - Concentration of CO2
• - Temperature
• Photosynthesis occurs in the chloroplasts of cells...
• There are 2 phases of photosynthesis:
• - Light Phase (light dependent)
• - Dark Phase (light independent)

DNA replication

• Semi - conservative:
• Each time a new cell is made, the cell must receive an exact copy of the
• parent cell DNA. The new cells then receive the instructions and info needed to function. The process of copying DNA is called replication. Replication occurs in a unique way –
• instead of copying a complete new strand of DNA, the process “saves” or
• conserves one of the original strand. For this reason, replication is called
• semi-conservative. When the DNA is ready to copy, the molecule “unzips” itself
• and new nucleotides are added to each side.
• 
• Caption: DNA replication

Respiration...

• glucose
• + oxygen à carbon dioxide + water + energy
• F

Factors affecting respiration...

• Oxygen:
• - respiration increases with more oxygen
• Respiration:
• - Respiration is very slow if water is low
• Type of substrate:
• - Glucose is preferred and is used immediately, then fats, then amico acids but these must be modified b4 use
• Temperature:
• - 30-35 deg is potimum for respitory enzymes. Very slow @ low temperatures due to low enzyme activity and over 50deg enzymes become denatured

Life Processes

• Transport - diffusion = high concentration to low concentration * facilitated diffusion!
• - Osmosis - water thru semi-permeable membrane
• - active transport- uses ENERGY/ ATP to move substances AGAINST concentration gradient
• Enzymes in respiration or photosynthesis
• Substrates = reactants = Glucose + CO2 (respiration)
• CO2 + H2O (photosynthesis)
• = products = CO2 + H20 + ATP (respiration)
• = O2 + Glucose - starch (photosynthesis)
• Mitosis - My Toe - Growth & repair

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