ATP Formation, Photosynthesis, and Cellular Respiration
ATP Synthase
We Need Energy!!!All living things need energy. All cells need to produce that energy in order to power cellular activities (reactions)
Adenosine Triphosphate
ATP is an energy-storing molecule that is needed to power many cellular activities
It is made up of a base adenine, a sugar ribose, and 3 phosphate groups
ATP Formation
Protons move down the electrochemical gradient (from high concentration to low concentration)
Energy from the Hydrogen ions is transferred to ATP Synthase (the protein used in ATP formation) that energy is used to add a phosphate group to ADP (adenosine diphosphate) creating ATP (adenosine triphosphate) the high energy is stored in the bond between the last two phosphate groups
ATP Synthase
ATP Formation
ATP molecules then go on to power cellular activities By breaking the bond between the last 2 phosphate groups the high energy that was stored is then released
Powers Cellular Activities
ATP Formation
Location:ATP Synthesis happens in the
chloroplast and mitochondria
In the chloroplast most ATP is synthesized across the thylakoid membrane
In the mitochondria most ATP is synthesized across the inner membrane of the mitochondria
Photosynthesis:Converting Solar Energy
into a usable form.
6H2O + 6CO2 C6H12O6 + 6O2In plants, energy made in photosynthesis is stored as sugar. Energy required for metabolic activities and making other molecules.
Ex. Plants, algae, and certain bacteria (aka: producers)
Plants are autotrophs because they produce their own food (energy)
Plants sometimes make more sugar than they can use at one time. They will convert this sugar to starch for short and long term storage
Cyanobacteria
Plants serve as food for animalsCrop – a type of plant that is cultivated for use by humans Ex. Corn, tomatoes, peas, wheat, etc
6H2O + 6CO2 C6H12O6 + 6O2
How Photosynthesis Works• Photosynthesis occurs in chloroplasts which are tiny
green organelles found in Eukaryotic plant cells.– Thylakoids – located inside chloroplasts, are flattened
membrane-bound sacs. Stacked like coins or pancakes in columns called grana. Both are suspended in fluid matrix called stroma.
• Light is a form of radiant energy – energy that is transmitted in waves– Electromagnetic Spectrum – complete range of
radiant energy (ROYGBIV = visible light)
– All forms of radiant energy consists of tiny packets of energy called photons
• 3 things can happen to photons:1. Reflect – bounce off2. Absorb3. Transmit – pass through
Ex. In leaves – red and blue (and all other colors) light are absorbed, but green light which is reflected.
• Pigment – a molecule containing atoms that enable it to absorb light.– Ex. Chlorophyll (located in chloroplasts) – green
pigment found in photosynthesis – Ex. Carotenoids – pigment that produces a
yellow/orange color.
Carotenoids
Photosynthesis:Light-Dependent Reactions & Carbon Fixation (Calvin Cycle)
Photosynthesis: General Overview
Light-Dependent Reactions
Carbon Fixation(Calvin Cycle)
H2O
Light
C6H12O6
O2
ATP and NADPH
CO2
Carbon Fixation (Calvin Cycle)
Video Clip
Cellular Respiration: Glycolysis, Kreb’s Cycle, and the
Electron Transport Chain
Cellular Respiration – Overall Reaction
C6H12O6 + 6O2 6CO2 + 6H2O + energy
This equation is a simplified representation of cellular respiration. Actually, cellular respiration is a complex metabolic pathway, comprising at least 30 separate
steps. To understand respiration in detail we can break it up into 3 stages.
3 Stages of Cellular Respiration
Net ATP: 2 ATP 32 ATP2 ATP
The different stages of respiration take place in different parts of the cell. This allows the cell to keep the various metabolites
separate, and to control the stages more easily.
Points from the 3 stages diagram:
• The energy released by respiration is in the form of ATP (Adenosine Triphosphate)
• The release of carbon dioxide takes place before oxygen is involved. It is therefore not true to say that respiration turns oxygen into carbon dioxide; it is more correct to say that respiration turns glucose into carbon dioxide, and oxygen into water
• Stage 1 (glycolysis) is anaerobic respiration, while stages 2 and 3 are the aerobic stages.
Cellular Respiration
• Includes pathways that require oxygen• Glucose is oxidized and O2 is reduced• Glucose breakdown is therefore an
oxidation-reduction reaction• Breakdown of one glucose results in
roughly 36 to 38 ATP molecules
• An Oxidation-Reduction Process or REDOX Reaction
• Oxidation of GLUCOSE --> CO2 + H2O (e- removed from C6H12O6)
• Reduction O2 to H2O (e- passed to O2)
What Type of Process is Cellular Respiration?
• Metabolic Pathway that breaks down carbohydrates
• Process is Exergonic as High-energy Glucose is broken into CO2 and H2O
• Process is also Catabolic because larger Glucose breaks into smaller molecules
Other Cellular Respiration Facts
Mitochondria – The Power HouseMuch of respiration takes place in the mitochondria. Mitochondria have a double membrane:
• the outer membrane contains many protein channels called porins, which let almost any small molecule through
• the inner membrane is more normal and is impermeable to most materials. The inner membrane is highly folded into folds called christae, giving a larger surface area.
The electron microscope reveals blobs on the inner membrane, which were originally called stalked particles. These have now been identified as the enzyme complex that synthesises ATP, are is more correctly called ATP synthase. The space inside the inner membrane is called the matrix, and is where the Krebs cycle takes place. The matrix also contains DNA and some genes are replicated and expressed here.
Mitochondrial DNA – get only from Mom (exactly the same as mom)Nuclear DNA – get ½ from Mom & ½ from Dad
Aerobic and Anaerobic Respiration
glucose pyruvate
carbondioxide
water
oxygen
2 AD P+ 2 P i
34 ADP+ 34 P i
2 ATP 34 ATP
lactate
glycogenfa ts
aerobic partanaerobic part
• The first part of respiration is simply the breakdown of Glucose (6C) to a compound called Pyruvate (3C)
• This doesn’t require oxygen, so is described as anaerobic respiration (without air). It is also called glycolysis and it takes place in the cytoplasm of cells. It only produces 2 molecules of ATP per molecule of glucose.
• Normally pyruvate goes straight on to the aerobic part, but if there is no oxygen it is converted to lactate (or lactic acid) instead. Lactate stores a lot of energy, but it isn’t wasted : when oxygen is available it is converted back to pyruvate, which is then used in the aerobic part of respiration.
glucose pyruvate
carbondioxide
water
oxygen
2 AD P+ 2 P i
34 ADP+ 34 P i
2 ATP 34 ATP
lactate
glycogenfa ts
aerobic partanaerobic part
Aerobic and Anaerobic Respiration
• The second part of respiration is the complete oxidation of pyruvate to carbon dioxide and H2O. • Oxygen is needed for this, so it is described as aerobic respiration (with air). It takes place in the mitochondria of cells and produces far more ATP: 34 molecules of ATP per molecule of glucose.• Fats (mainly triglycerides) can also be used in aerobic respiration (but not anaerobic) to produce ATP
Total ATP from Cellular Respiration = 36 ATP molecules
A Little Krebs Cycle History• Discovered by Hans
Krebs in 1937• He received the Nobel
Prize in physiology or medicine in 1953 for his discovery
• Forced to leave Germany prior to WWII because he was Jewish
Copyright Cmassengale
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