PHOTOSYNTHESIS &

RESPIRATION

Introduction Vocab

Energy-ability to do work

Autotrophs-organisms able to capture energy from sunlight and produce their own food (producer)

Heterotrophs-organisms that obtain energy

from the food it consumes (consumer)

Energy

Comes in different forms: light, heat, & electricity Made when electrons move from high energy

orbitals to lower How do we store and release/transfer

energy? ATP-adenosine triphosphate (tri=3)

Stores energy ADP-adenosine diphosphate (di=2)

ATP & ADP ATP-adenine, ribose, and 3 phosphate ADP-adenine, ribose, and 2 phosphate Energy is stored between the bonds of

the 2nd and 3rd phosphate and transferred when broken

***ATP is the basic energy source of all cells -active transport -protein synthesis -muscle contractions -light produced by fireflies

ATP & ADP Continued…

Cells only have a small amount of ATP because it can’t be stored very well in the body

Cells are constantly regenerating ATP from ADP by using the energy in glucose

Glucose stores more than 90x chemical energy than ATP

Glucose is a product of photosynthesis and a reactant of respiration!!!

Requirements for Photosynthesis

1. Light “white light”-actually a mixture of different

wavelengths of light Ingenhousz & Priestly

Different wavelengths=different colors 2. Carbon Dioxide-from environment 3. Water-from environment 4. Chloroplast

Plants gather energy from sunlight with pigments chlorophyll (green) and carotene (reddish/orange) Chlorophyll doesn’t absorb green…green light is

reflected. Remember: light is energy, so when light is absorbed

so is its energy

Light & Pigments

As the chlorophyll in leaves decays in the autumn, the green color fades and is replaced by the oranges and reds of carotenoids.

500-600nm-very little light is absorbed. This light is in the green region of the spectrum,

and since it is reflected plants appear green. Chlorophyll absorbs so strongly that it can mask

other less intense colors

Photosynthesis

Plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates and produce oxygen as a waste product

6CO2 + 6H2O C6H12O6 + 6O2 Carbon Dioxide + Water Glucose + Oxygen

What’s missing???? Light (energy) and Chloroplasts!!

Photosynthesis Organelle:

Chloroplast Two reactions in

photosynthesis Light –Dependent Calvin Cycle

(Light-Independent)

Reactions of PhotosynthesisOrganelle: Chloroplast

LIGHT-DEPENDENTLIGHT-INDEPENDENT

-Location: Thylakoid Membrane

-Requires Light-Uses H20

-Produces Oxygen-ADP is converted to ATP-NADP+ is converted to

NADPH

-Location: Stroma

-Light not required-Uses CO2

-Produces Sugars-ATP is converted to ADP-NADPH is converted to

NADP+

Chloroplast

Light-Dependent Vocab Photosystem-cluster of chlorophyll &

pigments Electron Transport Chain -chain of

proteins that transfer high-energy electrons

Carrier Molecule -Compound that can accept a pair of high-energy electrons & transfer them to another molecule (NADP+ accepts electrons & H + ion, which turns it into NADPH)

Light-Dependent Reaction

Location: Thylakoid Membrane (Chloroplast)

Step 1: Light absorbed by photosystem II is used to break up water molecules into energized electrons, hydrogen ions (H+), and oxygen

Light-Dependent Reaction

Step 2: High-energy electrons from photosystem II move through the electron transport chain to photosystem I. As they lose energy, H+ ions are forced from the stroma into the thylakoid membrane through a protein.

Light-Dependent Reaction

Step 3: Electrons released by PSII are energized again in PSI. Enzymes in the membrane use the electrons to form NADPH from NADP+.

Light-Dependent Reaction

Step 4: Inside the thylakoid there are many positively charged H+ ions. The outside of the membrane is negative. The difference in charge provides energy to from ATP.

Light-Dependent Reaction

Step 5: As hydrogen (H+) ions pass through ATP synthase (carrier protein), their energy is used to convert ADP into ATP. ATP Synthase has to rotate to bind the P & ADP (energy).

Light-Dependent ReviewLocation: Thylakoid

Membrane-Requires Light-Uses H20

-Produces Oxygen-ADP is converted to

ATP (high energy)-energy stored

-NADP+ is converted to NADPH (high energy)-energy stored

http://www.youtube.com/watch?v=Oi2_n2wbB9o&feature=relatedhttp://www.science.smith.edu/departments/Biology/Bio231/ltrxn.html

http://www.youtube.com/watch?v=eY1ReqiYwYs

Recall:

Calvin Cycle (Light-Independent)

Location: Stroma 1st-CO2 enters from the environment 2nd-CO2 combines with 5-carbon molecule

to form two 3-carbon molecules 3rd-ATP and NADPH provide energy to

rearrange the 3-carbon molecules into higher energy forms ATP from Light-Dependent Reaction converted to

ADP NADPH from Light-Dependent Reaction

converted to NADP+

Calvin Cycle Continued…

3rd-The higher energy 3-carbon molecules have two options: 1. One will leave the Calvin Cycle to make sugars, lipids, or amino acids (so autotrophs can grow)or2. Five others get converted back to 5-carbon molecules to go through the cycle again

*Uses six CO2 molecules to make one glucose molecule (go back to the equation)

Calvin Cycle

Calvin Cycle Review

Location: Stroma in the chloroplast

Uses CO2 ATP is converted back

to ADP Energy was released

NADPH is converted back to NADP+ Energy was released

Photosynthesis Overview

sunlight & water O2

Light Dependent Reactions

Light Independent Reactions

NADP+

ADP

NADPHATP

Compounds for growth (Sugars)

CO2