cellular respiration. what is atp? energy used by all cells adenosine triphosphate organic molecule...
TRANSCRIPT
Cellular Respiration
What Is ATP?Energy used by all CellsEnergy used by all Cells
Adenosine TriphosphateAdenosine Triphosphate
Organic molecule containing Organic molecule containing high-energy Phosphate bondshigh-energy Phosphate bonds
Copyright Cmassengale
ATP for energyATP powers cellular work- made in photosynthesis
and cellular respiration A cell does three main kinds of work:
Mechanical work, beating of cilia, contraction of muscle cells, and movement of chromosomes(produces heat)
Transport work, pumping substances across membranes against the direction of spontaneous movement
Chemical work, driving endergonic reactions such as the synthesis of polymers from monomers
High Energy Electrons and Molecules
Electron Carrier: a molecule that picks up the electron and uses this energy to break apart bonds.Examples of electron carriers: NADP and ATPNADP captures two electrons of H and becomes NADPH.ADP becomes ATP!!!
How Do We Get Energy From How Do We Get Energy From ATP?ATP?
By breaking By breaking the highthe high--energy bonds energy bonds between the between the last two last two phosphates phosphates in ATPin ATP
Copyright Cmassengale
How Does ATP Work? So what? Energy is stored in these bonds. So? The breaking of the chemical bond releases the
energy
ATP + H2O→ ADP + P + ENERGY ATP is made in photosynthesis and respiration!!!
ATP (adenosine triphosphate) is a a molecule that carries energy that cells can use.
How Does ATP Work? The bonds between phosphate groups can be
broken by hydrolysis which produces energy!!!
ATP has 3 phosphate groups The bond to the third bond is easily broken. When the third bond is broken, energy is released. Becomes ADP – no energy!!
Chemical Structure of ATP
3 Phosphates
Ribose Sugar
Adenine Base
Copyright Cmassengale
What Does ATP Do for You?
It supplies YOU withIt supplies YOU with ENERGY!ENERGY!
Copyright Cmassengale
How Do We Get Energy From ATP?
By breaking By breaking the high- the high- energy energy bonds bonds between between the the last two last two phosphates phosphates in ATPin ATP
Copyright Cmassengale
What is the Process Called?HYDROLYSIS (Adding HHYDROLYSIS (Adding H22O)O)
H2O
Copyright Cmassengale
How Does That Happen?
An An Enzyme!Enzyme!
Copyright Cmassengale
How is ATP Re-Made?
The reverse of the previous The reverse of the previous process occurs.process occurs.
Another Another Enzyme is Enzyme is used!used!ATP SynthaseATP Synthase
Copyright Cmassengale
The ADP-ATP Cycle
ATP-ATP-asease
ATP ATP SynthaseSynthase
Copyright Cmassengale
When is ATP Made in the Body?
During a During a Process Process called called Cellular Cellular RespirationRespiration that takes that takes place in place in both both Plants Plants & Animals& Animals Copyright Cmassengale
Cellular Respiration The process in which cells turn food into usable energy in the form of ATP.
RELEASES CHEMICAL ENERGY FROM SUGARS AND OTHER CARBON-BASED MOLECULES TO MAKE ATP WHEN OXYGEN IS PRESENT!!!!NO OXYGEN – FERMENTATION!!!!
Cellular Respiration
The Purpose of Cellular Respiration
It is to make and break bonds to generate ATP and electrons.You end up with ATP, H ions and electrons.The electrons are sent to the Electron Transport Chain where they help to make ATP through ATP synthase.****Hydrogen ions are bonded with oxygen to make water which is used in photosynthesis.
Cellular Respiration Overview
Transformation of chemical energy in food into chemical energy cells can use: ATP
These reactions proceed the same way in plants and animals. Process is called cellular respiration
Overall Reaction:– C6H12O6 + 6O2 → 6CO2 + 6H2O
Overall Equation for Cellular Respiration
6CO6CO22 + 6H + 6H220 + e0 + e-- + 36- + 36-
3838ATP’sATP’s
CC66HH1212OO6 6 + 6O+ 6O22
YIELDSYIELDS
What are the Stages of Cellular Respiration?GlycolysisGlycolysisThe Krebs CycleThe Krebs CycleThe Electron Transport ChainThe Electron Transport Chain
Copyright Cmassengale
Cellular Respiration
Glycolysis – Occurs before Cell. Resp. Krebs Cycle (Citric Acid Cycle) Electron Transport Chain (ETC)
Glucose
Glycolysis Krebs cycle
Electrontransport
Fermentation (without oxygen)
Alcohol or lactic acid
Overall Reaction
C6H12O6 + 6O2 → 6CO2 + 6H2O + 38 ATP Overall this is a three stage process1. Glycolysis: before cellular respiration
• Occurs in the cytoplasm• Glucose is broken down
2. Krebs Cycle• Breaks down pyruvate into CO2• Occurs in mitochondrial matrix
3. Electron Transport Chain• ATP is synthesized - Occurs in mito membrane
FlowchartSection 9-2
Glucose(C6H1206)
+Oxygen
(02)
GlycolysisKrebsCycle
ElectronTransport
Chain
Carbon Dioxide
(CO2)+
Water(H2O)
+ATP
Cellular Respiration
Where Does Cellular Respiration Take Place?
It actually It actually takes place takes place in two parts in two parts of the cell:of the cell:
Glycolysis Glycolysis occurs in the occurs in the CytoplasmCytoplasmKrebs Cycle & Krebs Cycle & ETC TakeETC Take place place in the in the MitochondriaMitochondria
Copyright Cmassengale
GlycolysisDefinition: The process in which
one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound.
Glycolysis
Glyco = glucose Lysis = break down LOCATION: Occurs in the cytoplasm This stage occurs in BOTH aerobic
and anaerobic respirationOccurs in ALL eukaryotic
cells…
Glycolysis- ATP Production In the pathways beginning, 2 ATP
molecules are used up.At the end of glycolysis, 4 ATP
molecules are formed. NET GAIN- 2 molecules!!!
Glycolysis- NADH Production Process removes 4 high energy e- and
passes them to nicotinamide adenine dinuclueotide (NAD+), which is an electron carrier.
NAD+ turns into NADH while transferring electrons to other molecules.
Steps of Glycolysis
1.Two ATP molecules are used to energize a glucose molecule. 2. Glucose is split into 2 3-carbon molecules. Enzymes rearrange the molecules.3. Electrons are transferred to NADP. The carbon molecules are converted to pyruvate which enters cellular respiration.
Location= Cytoplasm NO O2 required Energy Yield net gain of 2 ATP at the
expense of 2 ATP 6-C glucose TWO 3-C pyruvates Free e- and H+ combine with organic ion
carriers called NAD+ NADH + H+
(nicotinamide dinucleotide)Used in ETC. Hydrogen attached to water.
Glycolysis
Glycolysis:
Get a sheet of paper to review theprocess of glycolysis.
Video: Glycolysis
Glucose
To the electron transport chain
Figure 9–3 GlycolysisGlycolysis:
Step 1
2 Pyruvic acid
Glycolysis Reactants and Products
Reactants 1 glucose Enzymes are needed 2 ATP are needed to
start
Products 2 Pyruvates (go to
next step) 4 ATP (2 are gained) 2 NADH (go to ETC)
Really 10 steps with 10 different enzymes involved.
Anaerobic Respiration (without oxygen): Fermentation
***fermentation does not make ATP for the cell, it cycles the ATP for glycolysis***(does not release energy in cell)
Two Main types:
1)Lactic Acid fermentation- converts pyruvic acid and NADH to lactic acid and NAD+
-muscle cells
2)Alcoholic fermentation- converts pyruvic acid and NADH to ethyl alcohol, CO2, NAD+
-yeast (air bubbles in bread)
Main Goals of Krebs Cycle Transfer high energy electrons(NADH
and FADH2) to molecules that can carry them to the electron transport chain.
• Form some ATP molecules.• Takes place in mitochondria
Review of Mitochondria Review of Mitochondria StructureStructure
SmoothSmooth outer outer MembraneMembrane
FoldedFolded inner inner membranemembrane
Folds called Folds called CristaeCristae
Space inside Space inside cristae called the cristae called the MatrixMatrix
Copyright Cmassengale
Krebs Cycle- Part A (Citric Acid Production)
From glycolysis, the 3carbon molecule (pyruvic acid/pyruvate) enters the mitochondria (innermost layer- Matrix)
3carbon pyruvic acid is broken down into 2carbon (Acetyl-CoA) molecules.
CO2 and NADH are produced Hint: anytime the number of carbons are
reduced, CO2 and NADH are produced
Acetyl-CoA (2carbon) combines with 4 carbon compounds forming a 6 carbon molecule Citric acid.
Krebs CyclePart B (Energy Extraction) The 6carbon Citric Acid broken down
into 5 carbon compound (releasing CO2 & NADH)
5 carbon compound broken down into 4 carbon compound (releasing CO2 & NADH)
In a series of 4carbon to 4carbon reactions, ATP, CO2, NADH & FADH2 are produced Remember: NADH & FADH2 are electron
carriers that will take the electrons to the ETC
Kreb Cycle
Krebs Cycle Reactants and Products
Reactants 2 Acetyl CoA (pyruvic
acid)
Remember when you form a bond energy is released!! This is the key!!
Products 2 ATP 8 NADH (go to ETC) 2 FADH2 (go to ETC)
6 CO2 (given off as waste)
Diagram of the ProcessDiagram of the Process
Occurs in Cytoplasm
Occurs in Matrix
Occurs across Cristae
Copyright Cmassengale
Krebs Cycle
Electron Transport Chain Where inner membrane of mitochondria
called cristea. Energy Yield Total of 32 ATP O2 combines with TWO H+ to form H2O
Exhale - CO2, H2O comes from cellular respiration
Video: ETC
Electron Transport ChainSection 9-2
Electron TransportHydrogen Ion Movement
ATP Production
ATP synthase
Channel
Inner Membrane
Matrix
Intermembrane Space
Mitochondrion
Electron Transport - Step 3
1. Proteins inside the membrane of the mito. Remove electrons from NADPh and FADH.
2. Electrons(hydrogen) are transported down the chain of the membrane to be pumped across.
3. ATP synthase(enzyme) puts a P on ADP to make ATP(END GOAL!!).
4. Oxygen enters the cycle to pick up electrons and hydrogen ions to make water that leaves the cycle.
Electron Transport Chain Electron carriers loaded with electrons and
protons from the Kreb’s cycle move to this chain-like a series of steps (staircase).
As electrons drop down stairs, energy released to form a total of 32 ATP – Final Goal!!
Oxygen waits at bottom of staircase, picks up electrons and protons and in doing so becomes water
Diagram of the ProcessDiagram of the Process
Occurs in Cytoplasm
Occurs in Matrix
Occurs across Cristae
Copyright Cmassengale
Energy Tally 36 ATP for aerobic vs. 2 ATP for anaerobic
Glycolysis 2 ATP
Kreb’s 2 ATP
Electron Transport 32 ATP 36 ATP
Anaerobic organisms can’t be too energetic but are important for global recycling of carbon
FlowchartSection 9-2
Glucose(C6H1206)
+Oxygen
(02)
GlycolysisKrebsCycle
ElectronTransport
Chain
Carbon Dioxide
(CO2)+
Water(H2O)
+ATP
Cellular Respiration