Photosynthesis & Cellular Respiration notes

WARM UP (4/4/16)
1. What organelles helps plants capture light energy from the sun and convert it into chemical energy?
2. What is this conversion from light energy to chemical energy in plants called?
3. How do autotrophs and heterotrophs obtain energy to grow?



Answers...
1. chloroplasts
2. photosynthesis
3. Autotrophs make organic compounds that serve as food for them and all other organisms on Earth, and have a supply of food as long as sunlight is available. Heterotrophs, however, must consume the food that autotrophs make since they cannot make their own.

OK...LET'S DO SCIENCE!

In Chapter 8 we learned about how cells maintain homeostasis by controlling movement of substances into and out of the cell & how cells communicate...

Now we want to explore how cells get the energy they need to do these tasks.

Begin Ch 9: Photosynthesis & Cellular Respiration

Learning Objective: I can describe the processes cells use to obtain energy.

PHOTOSYNTHESIS: The process by which carbon dioxide, sunlight, and water are converted into carbohydrates and oxygen

-Who does it? plants, algae, & some prokaryotes (we'll focus on plants)

-Where does it occur? inside the chloroplasts, organelles found in plant cells

-Why is it important? it produces glucose and oxygen which are needed for cellular respiration (and sustains all life on earth!)

OVERVIEW OF PROCESS:

carbon dioxide + water + light energy from sun ----> glucose (sugar) + oxygen

Chemical equation:

6CO2 + 6H2O + light energy ------> C6H12O6 + 6O2

THREE STAGES OF PHOTOSYNTHESIS:

1. Light Reactions - energy from the sun is used to split water in an H+ (hydrogen ion) and an O2; oxygen diffuses out of chloroplasts as a byproduct.

2. Light energy is converted to chemical energy; temporarily stored in ATP (adenosine triphosphate) & NADPH (nicotinamide adenine dinucleotide phosphate)

3. Calvin Cycle - carbon is fixed into glucose; fixed = converting inorganic compounds like carbon dioxide into organic compounds like glucose

(left side processing)

CELLULAR RESPIRATION: Process used by humans and most other organisms to release the energy stored in the food they consume.

-Who does it? All living organisms

-Where does it occur? Step 1 occurs in cytoplasm, the rest of the process occurs in the mitochondria of plant & animal cells

-Why is it important? It produces ATP, the fuel needed by cells to perform all necessary functions and maintain life!

OVERVIEW OF PROCESS:

glucose + oxygen ---> carbon dioxide + water + energy

Chemical equation:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP (energy)

THREE STAGES OF CELLULAR RESPIRATION:

1. Glycolysis: occurs in cytoplasm of plant & animal cells; glucose is broken down into 2 pyruvate molecules.

2. Krebs Cycle: takes place in the matrix (inside) of a cell's mitochondria; breaks down pyruvate into carbon dioxide, or CO₂.

3. Electron Transport Chain: takes place in the inner mitochondrial membrane of cells; electrons and hydrogen ions (H+) are shuttled across the mitochondrial membrane to produce ATP for energy.

(left side processing)


Notes available to print out here

-These videos will give a general overview of the similarities/differences:photosynthesis vs. cellular respiration   photsynthesis & food

-Honors presentations?