chapter objectives you will learn what atp is you will explain how atp provides energy for the...
TRANSCRIPT
Chapter Objectives
You will learn what ATP is You will explain how ATP provides
energy for the cellYou will describe how chloroplasts
trap the sun’s energy to make ATP and complex carbohydrates
You will compare ATP production in mitochondria and chloroplasts
Cell RespirationCells need energy to do work and
to stay aliveMost of the energy comes from
carbohydrates (starches & sugars)Carbohydrates are turned into
glucose by digestionGlucose is taken apart chemically
and energy is released
ATP and RespirationEnergy needed by the cell is
stored in a special molecule
Adenosine triphosphate
Molecule has 3 phosphate groupsRemoving one of the phosphate
groups breaks the chemical bond and releases lots of energy
When one phosphate group is removed it becomes
Adenosine diphosphate
ADP
Turns back into ATP by bonding back the phosphate group that was removed
Energy to do this comes from glucose when it is broken down chemically
Glucose is broken down in the cytoplasm
The ATP-----ADP cycle occurs in the mitochondria
Energy Cycle
Energy + phosphate Energy + phosphate
ATP
ADP
Steps in Cell Respiration
1. First step is called Glycolysis
2. 1 glucose molecule is broken down into 2 molecules of pyruvic acid
3. Enough energy is released to change 2 molecules of ADP into 2 molecules of ATP
Glycolysis
Glucose
2 ATP
Pyruvic AcidPyruvic Acid
Second Step is Aerobic Respiration
Requires oxygen
2 Steps involved:a.) Citric Acid Cycle (Kreb’s Cycle)
b.) Electron Transport Chain (ETC)
Citric Acid Cycle
Begins and ends with the same molecule (Acetyl-CoA)
Pyruvate (formed during glycolysis) enters mitochondria and transforms to Acetyl-CoA.
CO2 is formed
2 ATP and Hydrogen (H+) ions are formed
Electron Transport Chain (ETC)
Located on inner membrane of Mitochondria
H atoms pass along long chain to produce 34 ATP
Hydrogen atoms passed to O2 at final electron acceptor to convert the ADP into ATP and form H2O
Aerobic Respiration
Pyruvate
36 ATPCarbon Dioxide
Water
Respiration in Review
Total of 38 molecules of ATP are produced by the 3 steps:
2 ATP from breakdown of glycolysis
2 ATP from breakdown of acetyl-CoA (Krebs Cycle)
34 ATP from E.T.C.
Chemical Equation for Cell Respiration
ADP + P + C6H1206 + 6 02 6CO2 + 6H20 +ATP
Anaerobic Respiration
First step like aerobic respiration Second step
1. Pyruvic acid is broken down into CO2
and either alcohol or lactic acid.
2. During this step no additional energy
is released Net energy produced is only 2 ATP
Molecules produced in step one
Breaking down glucose w/out oxygen
FERMENTATION
Anaerobic process that breaks glucose down into alcohol or lactic acid, CO2 and energy.
Takes place in the absence of oxygenCell only gets 2 ATP (very
inefficient)Uses for humans: wine, beer, bread,
cheese
Anaerobic Respiration
2 A TP M o lecu les
N o A TP C arb on D ioxid e + A lcoh o l o r L ac tic A c id
P yru vic A c id P yru vic A c id
Glucose
Lactic Acid when produced in muscle cells causes them to fatigue very rapidly.
Review of Respiration
ATP is the energy molecule obtained by the break down of glucose. Specifically 2 ATP are formed
When Pyruvic acid is broken down it forms 36 ATP molecules Carbon Dioxide and Water
Photosynthesis
Photosynthesis is the process used by plants to :
Obtain the energy needed by organisms and cells
Capture solar energy and change it to usable chemical energy
Photosynthesis Chemical Equation
6 CO2 + 6 H20 C6H12O6 + 6 O2
LIGHT CHLOROPHYLL
Photosynthesis occurs in the plant cell chloroplasts
Inside chloroplasts are many folded membranes called grana
Chlorophyll molecules inside of grana trap solar energy
Surrounding the grana is a solution called stroma
Photosynthesis Occurs in two major reactions
Light ReactionsDark Reactions
Light ReactionsOccur only in lightChlorophyll traps sunlightEnergy is used to change ADP into ATPEnergy in ATP is used in second series of
reactions, used by the cell or storedA second carrier molecule is also
produced
NADPH2
Light Reactions Continued
Occur in the thylakoid membrane and grana of chloroplasts.
Water splits to form hydrogen and oxygen which is then released
H2O H2 + O2
Dark Reactions (Calvin Cycle)
Known as Calvin CycleOccurs in both light and darkTakes place in the stroma of
chloroplastEnergy from ATP and NADPH2
is used to produce glucose and oxygen from water and carbon dioxide
Dark Reactions Continued
Hydrogen combines with carbon dioxide and other compounds to produce glucose
This reaction occurs after the light reactions
Comparing Photosynthesis & Respiration
Photosynthesis1. Occurs only when
light and chlorophyll are present
2. Stores energy in glucose
3. Uses carbon dioxide and water
4. Produces glucose and oxygen
6CO2+ 6H20 C6H12 O6 +
6O2
Respiration1. Occurs in all cells with or
without light & chlorophyll
2. Takes energy from glucose3. Uses glucose and oxygen4. Produces Carbon dioxide
& water
ADP + P +C6H12O6 + 02
CO2 + H20 + ATP
Organisms and their food needs
AutotrophAn organism that
makes its own food
For example: plants
HeterotrophAn organism that
does not make its own food but depends on autotrophs.
For example: humans