Notes on Photosynthesis

Standard: SB3 – Students will derive the relationship between single-celled and multi-celled organisms and the increasing complexity of systems.

What is Metabolism? Metabolism - All of the chemical reactions that occur within an organism. There are 2 types of metabolic reactions: 1. Catabolic 2. Anabolic

Catabolic - releases energy by breaking down larger molecules into smaller molecules.

Example of Catabolic Reaction: Cellular Respiration - Catabolic pathway in which organic molecules are broken down to release energy for use by the cell C6H12O6 + O2  CO2 + H2O + ATP Glucose Oxygen Carbon Dioxide Water Energy

Ever hear about “Anabolic Steroids” in the news? Anabolic - uses energy released by catabolic pathways to build larger molecules from smaller molecules Ever hear about “Anabolic Steroids” in the news? Building up

Example of Anabolic Reaction: Photosynthesis - two-phase anabolic pathway in which the sun’s light energy is converted to chemical energy for use by the cell. CO2 + H2O  C6H12O6 + O2 Carbon Dioxide Sun Light Water Glucose Oxygen

What is Metabolism? The relationship of anabolic and catabolic pathways results in the continual flow of energy within organisms.

Energy and Life: All living organisms require energy

Living organisms are divided into 2 groups according to the way they get food: 1. autotrophs auto = self troph = feeder

a. Photosynthesis – green plants and algae

b. Chemosynthesis – uses energy from inorganic chemical reactions ex. some bacteria

2. heterotrophs hetero = other troph = feeder animals either herbivores or carnivores

fungi (non-green; plant-like)

parasites – lives off host

saprophytes – lives on dead or nonliving organic matter

most bacteria

Energy Transfer Compounds: ATP (adenosine triphosphate) – main chemical compound that living things use to store energy

Why is ATP needed? 1. Light enters too rapidly for the cell to store it all in glucose 2. Energy is released in respiration too rapidly to be used

ATP is made up of a nitrogen-containing compound called adenine, a 5-carbon sugar called ribose, and 3 phosphate groups Adenine Phosphate groups Ribose

adenine – ribose – P ≈ P ≈ P ≈ high energy bond adenine – ribose – P ≈ P ≈ P nitrogen base 5-carbon sugar phosphate groups

ATP Structure ATP = Adenosine TriPhosphate Adenine Ribose 3 Phosphate groups High Energy Bonds Adenosine

ATP ADP – adenosine diphosphate AMP – adenosine monophosphate

Energy stored in ATP is released when ATP is converted into ADP + a phosphate group

ATP-ADP Cycle ADP ATP Partially charged battery Fully charged battery Energy Energy Adenosine diphosphate + phosphate Adenosine triphosphate Partially charged battery Fully charged battery

ATP is holding the ENERGY in the last phosphate…. Pop off the last one! When the last phosphate is POPPED off, it releases energy for the cell to use… & turns into ADP

ATP Cycle ATP ADP photosynthesis nerve conduction respiration A-P≈P≈P photosynthesis nerve conduction respiration active transport ADP A-P≈P

Most cells only have enough ATP to last for a short-lived activity ATP can not be stored for long periods of time Whenever a cell needs energy it can change ADP and glucose to ATP

Where does ATP come from? Mitochondria (in plants & animals) break down food (glucose) to make ATP (ENERGY). An animal (consumer) must EAT a plant to get the food (glucose). Where does the food (glucose) come from? Photosynthesis in plants

ATP & ADP Video

PLANTS BY PHOTOSYNTHESIS Energy Flow Chart active transport light energy Muscle contraction ALL OF LIFE’s PROCESSES!!! DNA synthesis Protein synthesis Cell division In the bonds of ATP PLANTS BY PHOTOSYNTHESIS chemical energy chemical energy chemical energy chemical energy chemical energy chemical energy In the bonds of GLUCOSE chemical energy chemical energy chemical energy chemical energy ALL ORGANISMS BY CELL RESPIRATION chemical energy

Brief Photosynthesis Video

Photosynthesis photo = light synthesis = put together (make complex from simple) Click image for video

Photosynthesis – the process by which green plants combine CO2 and H2O in the presence of chlorophyll and light energy to form glucose and release O2

Equation for photosynthesis: 6CO2 + 6H2O C6H12O6 + 6O2 reactants products

Raw materials – CO2 and H2O (both are inorganic) Product – glucose, which is organic

Photosynthesis requires light and chlorophyll Light (radiant) energy is changed to the chemical bond (stored) energy of glucose

The light energy transferred to the electrons in the chlorophyll molecule raises the energy level of the electrons providing the energy for photosynthesis to begin Chlorophyll acts as a catalyst

Photosynthesis takes place inside the chloroplasts

contain chlorophyll have a double layer of phospholipids and proteins

chloroplasts contain saclike photosynthetic membrane called thylakoids

thylakoids are arranged in stacks called grana

solution inside chloroplast called stroma

Photosynthesis is broken down into 2 stages: 1. Light-dependent reactions – take place in thylakoid membrane 2. Calvin Cycle – uses ATP and NADPH from light-dependent reactions to produce high energy sugars (glucose)

Summary of light-dependent reaction: a. Chlorophyll traps energy Kinetic (light) – stored as potential (chemical) b. Water splits  2H+ + O-2

c. ADP to ATP (stores energy) d. O2 is released

V B G Y O R Absorption of Light by Chlorophyll a and Chlorophyll b

Summary of Calvin Cycle: a. Does not require light b. “Fixing of a carbon in a carbohydrate”

Photosynthesis: An Overview Water CO2 Light Chloroplast NADP+ ADP + P Calvin Cycle Light- Dependent Reactions ATP NADPH Sugars O2

Factors affecting photosynthesis 1. shortage of water 2. temperature (0º to 35º C) 3. intensity of light

6H2O + 6CO2 → 6O2 + C6H12O6 Photosynthesis Concept Map Write the complete chemical reaction here… reactants and products 6H2O + 6CO2 → 6O2 + C6H12O6 Photosynthesis Includes two stages Light- dependent reactions Calvin cycle takes place in uses use take place in Energy from Sunlight, H2O Thylakoid membranes Stroma ATP NADPH to produce of to produce High-energy sugar ATP NADPH O2 Chloroplasts goes into the atmosphere! goes into plant roots, for ex. NOTICE THIS…

Detailed Photosynthesis Video

Click here for corny music video Respiration Cellular Respiration – chemical energy from glucose and other food is released in a chemical pathway to control the speed and amount includes all the chemical reactions in which energy is released in support of cell life Click here for corny music video

Where does the energy come from? the sun (stored in the chemical bonds of glucose) photosynthesis is energy storing respiration is energy releasing

Equation for Respiration: respiratory C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP enzymes Respiration is the opposite of photosynthesis Respiration occurs in the mitochondrion

There are 2 main stages of Cellular Respiration: 1. Glycolysis – (anaerobic) occurs in the cytoplasm

glycolysis produces 2 ATPs/glucose

2. Aerobic – (Krebs cycle and electron transport chain) occurs in mitochondrion

for every turn of the Krebs cycle 1 ATP is generated Click here for a Khanacademy review from youtube, 18 minutes

Cellular Respiration: An Overview Electrons carried in NADH Electrons carried in NADH and FADH2 Pyruvic acid Glucose Electron Transport Chain Krebs Cycle Glycolysis Mitochondrion Cytoplasm 2 2 34

Krebs, Electron Transport Chain pyruvic acid, electrons Cell Respiration Concept Map Concept Map 6O2 + C6H12O6 → 6H2O + 6CO2 Write the complete chemical reaction here… reactants and products Cell Respiration includes Krebs, Electron Transport Chain glycolysis takes place in uses uses take place in Membranes (cristae) pyruvic acid, electrons glucose Cytoplasm oxygen to produce of to produce 36 ATP! (total) pyruvic acid electrons 2 ATP Mitochondrion Carbon dioxide, water goes into atmosphere NOTICE THIS…

If after glycolysis, oxygen is still absent – fermentation results (anaerobic respiration) 2 forms of fermentation: 1. Lactic acid – occurs in animal cells (bacteria) accumulates in tissues – muscles, results in fatigue

Examples – yogurt, buttermilk, sauerkraut, dill pickles 2. Alcohol – occurs in plants such as yeast end product – ethyl alcohol

Examples – brewing and baking In both forms of fermentation, the energy of glucose remains in the products: lactic acid and alcohol

Chemical Pathways for Cell Respiration Glucose With oxygen Krebs cycle Electron transport Glycolysis Without oxygen =reactants = products Alcoholic or lactic acid Fermentation Which pathway makes more ATP—with oxygen or without? Why would a cell have the other option, then?

ATP yield: Glycolysis - 2 Krebs cycle - 2 Electron transport - 34 _____________________ Total = 38

ATP stored energy is used to: 1. Build starches, fats and oils, nucleic acids, and proteins 2. Supports cell activities: a. active transport b. cell division c. nerve transmission

d. biosynthesis (assimilation and photosynthesis) e. muscle contraction f. bioluminescence

4. 3. (structure) 2. (structure) 5. 6. 7. 8. 1.

Photosynthesis: An Overview NADP+ ADP + P Calvin Cycle Light- Dependent Reactions ATP NADPH

Cellular Respiration: An Overview Electrons carried in NADH Electrons carried in NADH and FADH2 Pyruvic acid Krebs Cycle Go to Section:

ATP ATP Structure ATP =

Chemical Pathways for Cell Respiration Alcoholic or lactic acid

Photosynthesis Concept Map includes takes place in uses use take place in to produce of to produce

Cell Respiration Concept Map Section 8-3 Cell Respiration includes takes place in uses uses take place in to produce of to produce goes into atmosphere