photosynthesis and respiration
DESCRIPTION
Photosynthesis and Respiration. Chapter 6. Photosynthesis. The process by which plants convert the energy of sunlight into the energy of chemical bonds (sugar and starch) Plants make organic compounds (Carbs) from inorganic compounds (Water and CO2). The equation. - PowerPoint PPT PresentationTRANSCRIPT
Photosynthesis and Respiration
Chapter 6
Photosynthesis The process by which plants convert the
energy of sunlight into the energy of chemical bonds (sugar and starch)
Plants make organic compounds (Carbs) from inorganic compounds (Water and CO2)
The equation Carbon Dioxide + water sugar + Oxygen CO2 + H20 C6H12O6 + O2
Sunlight All organism depend on sunlight for energy
Autotrophs – directly depend on energy to make food
Heterotrophs – indirectly depend on energy because they need to consume autotrophs
Pigments Colored substances that absorb or reflect
light Capture the light energy to be used by the
cell Found in chloroplasts Chlorophyll – appears green
Energy storing compounds When pigments absorb light they boost
electrons to a higher energy level They either are picked up by an electron
carrier NADP+ NADPH Or they are used to make Adenosine
Triphosphate (ATP) from AMP or ADP
Complete the following in your purple book
Pg 117 #1-4 and problem solving
Project topics DNA RNA (protein Synthesis) Mitosis Meiosis Gregor Mendel Karyotypes and Punnett
Suqares Human Genome project Selective breeding
(transgenic plants and animals)
Sex-linked traits Non-disjunction disorders Mutations Hemophilia & Muscular
Dystrophy Kleinfelters and Turner
syndrome Dwarfism & Downs
Syndrome Genetic Engineering Evolution (Darwin)
Photosynthesis – the process Two parts 1) light reaction – Captures light energy and
converts it to stored energy (NADPH or ATP) Requires sunlight
2) Dark reaction – used stored energy to convert CO2 into sugar
Light Reaction Photosynthetic membrane – membrane
within the chloroplast Contains Photosystems –clusters of
pigment molecules (both chlorophyll and accessory pigments)
Photosystem I and Photosystem II
When photosystems are hit with sunlight
electrons are boosted and released These electrons are picked up by NADP+
and ADP These storage molecules will be used to
fuel the dark reaction
Electron transport chain (ETC) In order to be picked up by electron carriers
the molecules must pass down the ETC Electrons released by Chlorophyll will be
replaced by the breakdown of water Oxygen from the breakdown of water is
released as waste
Summary of the light reaction Light hits a photosystem within the
chloroplast and boosts the electron level These electrons are passed down the ETC
and picked up by NADP+ and ADP The electrons are replaced by the
breakdown of water Oxygen is a waste product
???? What is the formula for photosynthesis? What are the reactants? What are the products? What is the main pigment used in
photosynthesis? What replaces the electrons lost in the light
reaction? What two molecules pick up electrons and take
them down the ETC to the dark reaction?
The dark reaction Light does not play a direct part in the
reaction Also known as the Calvin cycle
Five steps of the Calvin Cycle 1st - 3(CO2) combines with a 3(5C)
molecules and form 3 (6C) molecules 2nd – The 6C molecules split and make 6
(3C) molecules 3rd – The molecules rearrange to make 6
(3C) molecules called PGAL NADPH and ATP are used
4th – 1 PGAL is released and 5 PGAL move
on 5th – the 5 (3C) PGAL molecules rearrange
to form 3 (5C) molecules The cycle repeats
Glycolysis and Respiration Break down of sugar Glycolysis – sugar is not completely broken
down Respiration – sugar is completely broken
down C6H12O6 + 6O2 6CO2 + + 6H20
3(CO2)
3(5C) 3(6C)
6(3C)
6 PGAL(3C)
1PGAL (3C)
5 PGAL (3C)
Groups Names Topic Textbook pages 8-10 facts
Questions?????? How does the formula for respiration
compare to the formula for photosynthesis? How do they differ in their use/release of
energy? Write this equation using words. What are the reactants for respiration? What are the products for respiration?
Glycolysis Initial breakdown of glucose molecule 6C sugar is broken down into 2 (3C) PGAL
molecules 2 ATP molecules are needed for this to occur These two PGAL are then converted to pyruvic
acid also a 3C molecule 4 ATP and 2 NADH are produced There is a net gain of 2 ATP and 2 NADH
Respiration If Oxygen is available Respiration will occur In this process the two pyruvic acid
produced during glycolysis are further broken down during the Krebs cycle
This process takes place in the inner membrane of the mitochondria
Steps of the Krebs cycle 1st – Pyruvic acid (3C) is converted to
acetyl-CoA a 2C molecule; 1 CO2 is released
2nd – the acetyl CoA enters the Krebs cycle and joins with a 4C molecule to create a citric acid a 6C molecule
3rd – This 6C molecule is converted to a 5 C molecule by releasing 1 CO2 and NADH
4th - This 5C molecule is converted to a 4C
molecule by releasing 1 CO2 and NADH 5th – This 4C molecule is further
transformed creating 1GTP, 1 NADH and 1FADH2
The cycle begins again
Overview of Respiration 2 Carbon atoms are added in the form of
pyruvic acid 2 Carbon atoms are removed in the from of
CO2 3 NADH, 1FADH2 and 1 GTP molecules
are formed 2 turns yield 6NADH, 2 FADH2 and 2 GTP
ETC Electrons from electron carriers (NADH,
FADH2 and GTP) are passed down an ETC to form ATP
1 GTP – 1 ATP 1 NADH – 3 ATP 1 FADH2 – 2 ATP
ATP yield
Intermediate reaction 2 NADH – 6 ATP
Krebs Cycle 2 GTP – 2 ATP 6 NADH – 18 ATP 2 FADH2 – 4 ATP
Fermentation If cells do not have Oxygen they can not
enter the intermediate step nor the Krebs cycle
They will perform fermentation Fermentation does not require Oxygen and
simply changes pyruvic acid to a more useful
Types of fermentation Lactic acid fermentation
Muscles
Alcoholic fermentation Yeast
Uses the NADH produced in glycolysis Yields 2ATP