Carbon dioxide

C6H12O6

Photosynthesis

H2OCO2 O2

Water

+ 66

Lightenergy

Oxygen gasGlucose

+ 6

Photosynthesis

Chapter 8

Do you remember any of the eight characteristics of living things?

1. Living things are based on a universal genetic code (DNA)

2. Living things grow and develop3. Living things respond to their environment

(stimulus)4. Living things reproduce5. Living things maintain a stable internal

environment (homeostasis)6. Living things obtain and use material and energy

(metabolism)7. Living things are made up of CELLS8. Taken as a group, living things evolve over time

Three Subatomic Particles

Proton: (+) charged particle found inside the nucleus

Neutron: neutral particle found inside the nucleus

Electron: (-) charged particle found outside the nucleus in various energy levels

Organic Compounds

Carbohydrates

Monomer:Monosaccharide

Made up of:Carbon, Hydrogen,

Oxygen (H:O in 2:1 ratio)

Sugars – glucose, fructose, sucrose

Lipids

Monomer: Glycerol and Fatty Acids

Made up of: Carbon, Hydrogen,

Oxygen(H:O not in 2:1 ratio)

Oils, Waxes, Butter

Proteins

Monomer: Amino Acid

Made up of: Carbon, Hydrogen, Oxygen, Nitrogen

Enzymes

Nucleic Acids

Monomer: Nucleotide

1) 5 Carbon sugar, 2) phosphate group 3)nitrogenous base

Made up of: Carbon, Hydrogen,

Oxygen, Nitrogen and Phosphorus

DNA and RNA

Differences between plant and animal

Plant Animal

Cell wall Chloroplast Photosynthesis Lysosomes only in

specialized cells No centrioles

No cell wall No chloroplast No photosynthesis Lysosomes Centrioles (cell

division)

Organelle for photosynthesis – chloroplast Organelle to convert chemical energy into

energy the cell can use – mitochondria Energy currency of the cell – ATP Why are plants green? Chlorophyll

Autotrophs and Heterotrophs: Autotrophs

Organisms that manufacture their own food (Plants) Also known as producers

Heterotrophs Organisms that cannot make their own

food (Humans) Also known as consumers

Autotrophs and Photosynthesis: Autotrophs use the energy directly from sunlight

and store it in organic compounds. They convert solar energy to chemical energy

stored in carbohydrates (glucose). Photosynthesis is a series of complex reactions in which the product of one reaction is consumed in the next reaction. A series of reactions linked in this way is called a biochemical pathway.

Biochemical Pathway:

Equations: Photosynthesis: (stores energy)

6 CO2 + 6 H2O C6H12O6 + 6 O2

Cellular Respiration: (releases energy)

C6H12O6 + 6 O2 6 CO2 + 6 H2O + ATP

glucose

glucose

Photosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

LIGHT

Carbon Dioxide

Water

Glucose

Oxygen

What is Light?

Light Speed, c = 2.9979 x 108 m/s

or 670.6 million mph

Which type of light carries more energy, blue or red?

• Light travels through space as waves of energy.

• Different colors have different wavelengths.

Why are plants usually green?

Electromagnetic Spectrum• Wave length and energy are inversely

proportional

• The smaller the wave length, the more energy

• Blue light is high energy

• Red light is low energy

They reflect green light

Photosynthesis Takes place in the chloroplast Thylakoids – saclike

photosynthetic membrane in the chloroplast

Grana – stacks of thylakoids

Stroma - the region outside of the thylakoid membranes

Plant (Chloroplast) Pigments Membranes of the thylakoid contain a variety

of pigments Pigments – light absorbing molecules Chlorophyll – the most abundant pigment in

plants that absorbs blue and red light. Chlorophyll a - blue-green pigment Chlorophyll b - yellow-green pigment

Accessory Pigments – absorb light in other regions of the spectrum Carotene - an orange pigment

Xanthophyll - a yellow pigment

Anthocyanin – a red pigment

Accessory Pigments Why do plants need accessory pigments?

They absorb light in other regions of the spectrum The accessory pigments are always present in

most plants but masked by the chlorophyll.

Pigments Why do leaves change color in the fall?

Answer: Shorter day lengths stop chlorophyll production, and expose accessory pigments

Chemical Energy and ATP: One of the most important compounds that cells

use to store and release energy is adenosine triphosphate (ATP).

ATP consists of adenine, a 5-carbon sugar called ribose, and three phosphate groups.

Why is ATP useful to cells?

ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups. This characteristic of ATP makes it exceptionally useful as a basic energy source for all cells.ATP Synthase (3:21)

ADP and ATP Cells store energy by adding a phosphate group to

adenosine diphosphate (ADP) molecules Cells release energy from ATP molecules by subtracting a phosphate group

The energy of ATP is locked in the bonds between the phosphate groups. When the terminal phosphate group of the ATP molecule

is removed by hydrolysis, energy is released and adenosine diphosphate (ADP) and phosphate are formed.

ATP Synthase (3:21)

Photosynthesis (Overall)

Light

CO2H2O Chloroplast

LIGHTREACTIONS(in thylakoids)

CALVINCYCLE

(in stroma)

NADP+

ADP

+ P

ATP

NADPH

O Sugar

Electrons

Light Dark

An Overview of Photosynthesis: Because light is a form of energy, any compound

that absorbs light absorbs energy. Chlorophyll absorbs visible light especially well.

When chlorophyll absorbs light, a large fraction of the light energy is transferred to electrons. These high-energy electrons make photosynthesis work.

Photosynthesis (3:39)

Light-Dependent Reactions: Photosynthesis involves two sets of reactions.

The first set of reactions is known as the light-dependent reactions because they require the direct involvement of light and light-absorbing pigments.

Light-Dependent Reactions: The light-dependent reactions use ENERGY from

sunlight to produce energy rich compounds, like ATP and NADPH. Water is required and Oxygen is a byproduct

These reactions take place within the THYLAKOID membranes of the chloroplast.

Light-Independent Reactions (Calvin Cycle):

Plants absorb carbon dioxide from the atmosphere and complete the process of photosynthesis by producing sugars and other carbohydrates.

During light-independent reactions, ATP and NADPH molecules produced in the light-dependent reactions are used to produce high-energy sugars from carbon dioxide.

Light-Independent Reactions: No light is required to power the light-

independent reactions.

The light-independent reactions take place outside the thylakoids, in the STROMA.

An Overview of Photosynthesis:

Sunlight

H2O

O2

CO2

Sugars (C6H12O6)

Photosynthesis Overview (7:26)

_____ + _____ _____ + _____6 CO2 6 H2O 6 O2 C6H12O6

Rate of Photosynthesis: Light Intensity:

Increase rate of photosynthesis, then levels off (maximum rate of photosynthesis) Higher intensity, excites more electrons in

chlorophyll @ some intensity, all available electrons are

excited

Rate of Photosynthesis: Temperature:

Higher temperature accelerates the chemical reactions.

Peaks @ certain temperature because the enzymes become ineffective and unstable

Rate of Photosynthesis: Amount of CO2:

Increases rate of photosynthesis to a point, then levels off

Water Availability: Increases rate of photosynthesis to a point, then

levels off

Biochemical Pathway:

Structure of the Chloroplast

Chemical Energy and Food

The two equations are exact opposites!

PHOTOSYNTHESIS

___________ + _________ + ___________ →_______________ + __________6 CO2 6 H2O C6H12O6 6O2

_____________ + _________ →________ + __________ + __________

CELLULAR RESPIRATIONC6H12O6 6O2

6 CO2 6 H2O

Structure of the Mitochondria:

Cellular Respiration

Chapter 9

Comparing Photosynthesis & Cellular Respiration:

Photosynthesis Cellular Respiration

Function

Location

Reactants

Products

Produces food (chemical energy) for the plant

(glucose C6H12O6)

Produces chemical energy (ATP) for the cell

Chloroplast Mitochondria

Water (H2O), Carbon dioxide (CO2)

and sunlight

Oxygen (O2) and Glucose (C6H12O6)

Oxygen (O2) and Glucose (C6H12O6)

Water (H2O), Carbon dioxide (CO2)

and energy (ATP)

Comparing Photosynthesis & Cellular Respiration:

Which type(s) of organisms carry out photosynthesis?

Autotroph Heterotroph

Which type(s) of organisms carry out cellular respiration?

Autotroph Heterotroph

Chemical Energy and Food

Cellular respiration happens slowly and in many steps.

If all the energy was release in one step… Most would be lost as light and heat! Cellular respiration breaks down glucose

molecules and banks their energy in ATP

An Overview of Cellular Respiration:

Stages of Cellular Respiration: The three main

stages of cellular respiration are

1. Glycolysis2. Krebs cycle3. Electron transport

chain.

Oxygen and Energy: Pathways of cellular

respiration that require oxygen are called AEROBIC. The Krebs cycle and electron transport chain are both aerobic processes. Both processes take place inside the mitochondria.

Oxygen and Energy: Glycolysis and fermentation

are anaerobic processes. They do not directly require oxygen, nor do they rely on an oxygen-requiring process to run. However, glycolysis is still considered part of cellular respiration. Glycolysis takes place in the cytoplasm of a cell.

Compare Photosynthesis to Cellular Respiration

NADH

NADH FADH2

GLYCOLYSISGlucose Pyruvate CITRIC

ACID CYCLE

OXIDATIVE

PHOSPHORYLATION

(Electron Transport

and Chemiosmosis)

Substrate-level phosphorylation

Oxidative phosphorylation

Mitochondrion

and

High-energy electrons carried by

NADH

ATPATPATP

CO2 CO2

Cytoplasm

Substrate-level phosphorylation

Light

CO2H2OChloroplast

LIGHTREACTIONS(in thylakoids)

CALVINCYCLE

(in stroma)

NADP+

ADP+P

ATP

NADPH

O Sugar

Electrons

How Cells Obtain Energy (14 min)