Cellular Respiration

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Transcript Cellular Respiration

Cellular Respiration
Making ATP
Cellular Respiration
Cell respiration is the controlled
release of energy from organic
compounds in cells to form ATP
Photosynthesis captures the energy of
light and traps it in sugars
In Cell Respiration the energy in a
sugar is used to make ATP
The two most important equations you will ever have to know
(at least while your in this class)
Cell Respiration Preview
Occurs with or without oxygen
Anaerobic
Respiration
(O2 absent)
1.
2.
Glycolysis
Fermentation
Aerobic Respiration
(O2 present)
1.
2.
3.
Glycolysis
Kreb’s Cycle
Oxidative
Phosphorylation
 Electron Transport
Chain
 Chemiosmosis
Reduction / Oxidation
Glycolysis
The breaking apart of a monosaccharide (sugar) to
form two 3-carbon molecules known as pyruvate.
2 ATP are formed and an energy rich electron is
donated to NAD+.
Reactants =
6-carbon sugar (glucose)
2 ATP
2 NAD+
Products =
2 x 3-carbon molecules (pyruvate)
4 ATP
2 NADH
Glycolysis
4 steps…

Phosphorylation

2 ATP donate phosphate groups to sugar
Lysis


6-C(arbon) sugar is broken into 2 3-C
compounds called pyruvate
Redox


(reduction/oxidation)
Electrons are released and accepted by
NAD+ to form NADH
ATP Formation


ATP is formed by substrate level
phosphorylation
Phosphorylation: addition
of a phosphate group, requires ATP
Lysis:
sugar split in half
Oxidation: loss of electron,
accepted by NAD+, becomes
NADH
ATP formation: ATP
created by substrate level
phosphorylation
Substrate Level Phosphorylation
The Link Reaction
Before pyruvate can enter
Kreb’s cycle it must be
converted to acetylCoA
Redox

(reduction/oxidation)

High energy edonated from
pyruvate to NAD+
Decarboxylation


The removal of
carbon
The Kreb’s Cycle
(Citric Acid Cycle)


Location:
mitochondrial
matrix
Purpose:
remove high
energy e- from
organic
molecules
Kreb’s Cycle

Requires:






8
1
3
1
1
1
different enzymes
acetyl-CoA (2 c)
NAD+
FADH
Oxaloacetate (4-c)
ADP

Produces


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
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1
3
1
1
2
Oxaloacetate
NADH
FADH2
ATP
CO2
Oxidative Phosphorylation
Electron Transport Chain

A series of proteins
embedded in the
inner-membrane of
the mitochondria

Uses energy from
electrons to pump
protons into intermembrane space
Chemiosmosis



Utilizes proton
gradient set up by
ETC
Requires ATP synthase
Couples proton
diffusion with
synthesis of ATP
Electron Transport Chain


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


Electron carriers (NADH & FADH2) donate
electrons to protein in membrane
Electrons are passed down protein chain
When electron is passed it loses energy
Loss of energy is used to pump protons
from matrix to inter-membrane space
The final destination for the electron is O2
O2 + 4e- + 4H+ = 2 H2O
Chemiosmosis
ATP Synthase
Anaerobic Respiration
Making energy without oxygen
Anaerobic Respiration
Fermentation
 Occurs after glycolysis when oxygen
is absent
 In yeast pyruvate is converted into
ethanol and CO2
 In humans lactic acid is produced
 Functions to recycle NAD+, which is
required for glycolysis



ATP is produce by
glycolysis
NADH must be
recycled to accept
more electrons
Pyruvate accepts efrom NADH, thus
recycling NAD+