Download presentation
Presentation is loading. Please wait.
1
Photosynthesis/Chemosynthesis
2
Autotrophs: Organisms that are capable of producing/creating their own food Photoautotrophs – sunlight drives the energy production process Chemoautotrophs – can extract energy from an inorganic substance
3
heterotrophs Organisms that need to get their energy from organic compounds already put together by other organisms
4
Photosynthesis Method by which autotrophs use their energy from the sun to create carbon compounds and energy rich molecules
5
Key Concepts Carbon-based compounds are the building block of energy stores Plants assemble these compounds through photosynthesis
6
Process Overview Water + Carbon Dioxide Oxygen + Glucose
12 H2O+ 6 CO2 6 O2 + C6H12O6 + 6 H2O Sunlight is trapped and converted into chemical energy (ATP) ATP delivers energy to reactions that create glucose Glucose units are combined to create starch and other materials
7
1st Stage: Light Dependent Reactions
Energy from the sun is captured and converted to ATP Water molecules are split Coenzyme (substance that aids an enzyme in reactions) NADP+ picks hydrogen particles and electrons forming NADPH (electron carrier)
8
2nd Stage: Light Independent Reactions
ATP donates energy so glucose can be formed from carbon, hydrogen, and oxygen The carbon and oxygen comes from carbon dioxide The hydrogen comes from the water via NADPH
9
Chloroplast Photosynthetic organelle found in photoautotrophs, site of photosynthesis
10
Stroma The interior of the chloroplast that contains the grana
11
THYLAKOID Flattened discs whose stacks are called the Granum/Grana
12
Pigments Molecules that absorb light Chlorophyll is the main pigment
13
Light Dependent Reactions – In Depth
1st stage of Photosynthesis: Pigments absorb sunlight and release electrons Electrons and hydrogen ions transfer energy that leads to ATP and NADPH formation The pigments that gave up electrons in the first place get electron replacements
14
Non-Cyclic ATP Formation
Photolysis: water molecules are split into oxygen, hydrogen ions, and electrons Oxygen released as a waste product The abundance of hydrogen ions creates an electrical/concentration gradient inside the thykaloid Combined force of gradients pumps ions out into stroma creating energy needed to create ATP out of ADP
15
Light Independent Reactions – In Depth
2nd Stage of Photosynthesis: “Calvin Benson Cycle” ATP molecules deliver energy ATP and NADPH molecules deliver the required hydrogen and electrons Carbon Dioxide provides the needed carbon and oxygen Can proceed in the dark as long as the above substrates are present
16
Calvin Benson Cycle: Carbon Dioxide diffuses across the membrane and is fixed to a five carbon compound (carbon fixation) This unstable six carbon compound is broken down and reformed into a six carbon sugar which can be formed into sucrose, starch, cellulose, etc.
17
Effects of the Environment
A) Light Intensity– as light intensity increase so does the rate of photosynthesis till all the pigments reach a saturation point B) Concentration of Carbon Dioxide – As CO2 concentration increases so does the rate of photosynthesis till all structures are being used at which point it levels out C) Temperature – There is an optimal temperature at which photosynthesis is most efficient, too extreme and it decreases (related to enzymes and water)
18
Chemosynthesis: Process by which bacteria get energy by pulling hydrogen and electrons from ammonium ions, iron or sulfur compounds, and other inorganic materials Get carbon from carbon dioxide
Similar presentations
© 2025 SlidePlayer.com Inc.
All rights reserved.