lipids into glycerol which enters the glycolitc pathway and into fatty acids .. which enter just prior to the Krebb cycle
Lipase enzymes break down
is an example of anabolism
The Pentose Phosphate Pathway
synthesis of complex molecules from simple molecules
anabolism
reverse
anabolism is the ___ of catabolism
the reverse of their catabolism
synthesis of proteins, neucleic acids, polysaccharides and lipids is
uses an intermediate from glycolosis to produce 5C sugars called pentoses
the pentose phosphate pathway
neucleotides
pentoses are used for the synthesis of
using light as an energy source to build complex molecules like glucose from CO2
photosynthesis is primarly a anabolic reaction
is a catabolic process.
oxidative phosphorylation
catabolic
catabolism
fermentation is also considered
CO2
fermentaion converts pyruvic acid into other 2 or 3 carbon molecules as well as
can either be anabolic or catabolic.
the reactions that occur between glucose and pyruvic acid
amino acids — which can be further broken down thru the gylcolosis and the kreb cycle pathways
proteins can be broken down by proteace enzymes into
nucleotides — can also enter the glucolysis pathway
neucleic acid can be broken down by neuclace enzymes into
glucose and further broken down by glycolysis and kreb cycles
polysaccharides and other sugars can be converted into
1. electron enters the chain from a primary donor
2. protons are extruded as Fe/S protein is reduced by FMNH2
3. Q-cycle reactions
4. As the terminal electron acceptor is reduced, electrons exit the chain
How aerobic resporation produces proton motive force.
This occurs in the cytoplasm of a cell.
how food relates to cellular respiration?
– blood vessels delivers fuel and oxygen
==> both go to a single muscle cell
food —> fuel burned in cells
energy and fuel is converted into ATP
cellular respiration
is made by an enzyme on the inner membrane of the mitochondrian
most ATP in a eukaryotic cell
an enzyme on the cytoplasmic membrane –> supports the theory that mitochondrian evolved from bacteria
a bacterium is similar in size to a mitochondrian and its ATP is formed by
muscle contraction or making new cell wall material for bacterial reproduction
ATP powers the work of the cell… such as
— NADH and ATP
glycolysis – glucose — pyruvic acid
1. some energy in the form of ATP must be invested in order to split the otherwise stable glucose molecule
2. NAD+
2. NAD+
glycolysis
takes place in the cytoplasm of both bacterial and eukaryotic cells
6C cell molecule
step 1. glycolysis
How ATP is produced from a molecule of glucose .. a common fuel for both humans and bacteria
transport electrons to the electron transport chain where more ATPs will be made
electron carriers
for every glucose molecules only 2 net ATP’s are produced in glycolysis
1 glucose: 2 net ATP
Final step of glycolysis some ATP is produced but not much
has produced two, 3C pyruvic acid molecules which still have a lot of energy available
end result glycolysis
pyruvic molecules into muscle cells mitochondrian … most of the energy is extracted ______
1C and 2O are removed ==> CO2 as a byproduct — then electrons are stripped forming NADH
pyruvic molecules enter mitochondrian
acetyl coA
conenzyme A attaches to the 2C fragment forming
cytoplasm … since bacteria do not have mitochondrian
in bacteria, pyruvic acid is converted into acetyl coA in the
coenzyme A is removed — 2C skeleton is attached to existing 4C molecule which is produced at the end of the last turn of the kreb cycle
The Kreb Cycle
picks up electrons and hydrogen atoms from 1 of the 3C molecules
==> NADH
==> NADH
NAD+ is an electron carrier
the new 6C chain is partially broken down releasing CO2
this new 6C molecule serves as the starting point for the next round of the Kreb Cycle
– in humans this CO2 is exhaled as we breath
– in bacterium
– in bacterium
several electrons are captured by electron carriers and more CO2 is released
Kreb cycle
acetyl COA : 1 ATP
each turn of the Kreb cycle that begins with 1 acetyl coA produces 1 ATP
the Kreb cylce produces an additional 2 ATP per original glucose
1 glucose : 2 ATP
since each acetyl COA is derived from 1/2 of the original glucose molecule …
even more energy is available in the electrons that are being transported by electron carriers such as FADH 2 and NADH
these ATP are produced by substrate level phosphorolation …
will take their electrons and hydrogen ions to the electron transport chain
electron carriers such as FADH 2 and NADH
where more ATP is made in the process of oxidative phosphorolation
electron transport chain
inner membrane of the mitochondian in eukaryotic cells such as this muscle cell ( humans)
electron carriers such as NADH deliver their electrons to an electron transport chain embedded in the
in bacterium the the electron transport chain is located on the cytoplasmic membrane
most of which are proteins that exists in large complexes
the electron transport chain consist of a series of electron carriers,
electrons are tranfered from one e carrier to the next in the electron transport chain
– as electrons move along each step of the chain, they give up a bit of energy
– at the end of the chain the electrons are transferred to oxygen ==> water is formed as a byproduct
– at the end of the chain the electrons are transferred to oxygen ==> water is formed as a byproduct
path electrons take through the chain
which activates the production of ATP … these turbines in cell is where most ATP generated from food
ATP synthase turbine is spun by the energy flow of hydrogen ions
that ATP can power a biker up a trail, a bacterium to reproduce rapidly
cellular respiration generates 10 million ATP per second in just one cell!!
photosynthesis
6CO2 + 6H2O —> C6H12O6 + 6O2
plants, algae and some bacterium have another way to use and produce ATP —
lets follow an electron carrier in the next step of the process
while the Kreb circle starts another round with a second acetly COA
1. eating food provides fuel and building blocks for your body
2. after food is broken down in the digestive system, it is transported to cells via circulatory system
3. fuel molecules are broken down for further in glycolysis and the citric acid cycle (also called the Krebs cycle)
4. ATP is produced with the help of the electron transport chain
2. after food is broken down in the digestive system, it is transported to cells via circulatory system
3. fuel molecules are broken down for further in glycolysis and the citric acid cycle (also called the Krebs cycle)
4. ATP is produced with the help of the electron transport chain
How food fuels cellular respiration
1. Chemotrophy
A) organic chemicals (glucose, acetate, etc.)
B) inorganic chemicals
(H2, H2S, Fe2+, NH4+, etc)
A) organic chemicals (glucose, acetate, etc.)
B) inorganic chemicals
(H2, H2S, Fe2+, NH4+, etc)
Microbes may use different metabolic pathways to obtain their energy
Chemically
chemoorganotrophs —
(glucose +O2 –> CO2 + H2O) ==> ATP
(glucose +O2 –> CO2 + H2O) ==> ATP
example – fermentation
Chemotrophy as energy source in metabolic pathways
A) organic chemicals (glucose, acetate, etc.)
A) organic chemicals (glucose, acetate, etc.)
chemolithotrophs
(H2 + O2 –> H2O) ==> ATP
(H2 + O2 –> H2O) ==> ATP
example – respiration
Chemotrophy as energy source in metabolic pathways
B) inorganic chemicals
(H2, H2S, Fe2+, NH4+, etc)
B) inorganic chemicals
(H2, H2S, Fe2+, NH4+, etc)
2 types of Energy sources in metabolic pathways
A) chemicals
B) Light
Microbes may use different metabolic pathways to obtain their energy. This helps understand the basic differences between these types of pathways.
pump hydrogen ions across the membrane ==> area of high hydrogen ion concentration
the energy released by electrons through repeated oxidation reduction reactions as they are passed along the chain is used to
these ions diffuse back across the membrane through a turbine called ATP synthase
the hydrogen ions represent a reservoir of high potential energy
phototrophs (light) ==> ATP
Light as energy source in metabolic pathways
Phototrophy
growth factors
Organic micronutrients are commonly called __________.
Fermentation forms organic acids and takes place in the absence of oxygen, while respiration forms water and carbon dioxide in the presence of oxygen.
Distinguish how fermentation and respiration differ.
forms organic acids and takes place in the absence of oxygen,
fermentation
1. Loop is flamed to sterilize it
2. culture tube cap is removed
3. tube tip is flamed to sterilize it
4. sterilized portion of the loop is inserted into tube
5. tube tip is flamed a second time
6. tube is recapped, loop is sterilzed
2. culture tube cap is removed
3. tube tip is flamed to sterilize it
4. sterilized portion of the loop is inserted into tube
5. tube tip is flamed a second time
6. tube is recapped, loop is sterilzed
Steps in how to maintain culture sterility during the process of aseptic transfer.
forms water and carbon dioxide in the presence of oxygen.
respiration
concept map Complete!
https://www.dropbox.com/s/h2m4a2zqiq7we6f/Screenshot%202016-02-08%2022.53.54.png?dl=0
The Krebs cycle produces molecules necessary for function of the electron transport chain.
Based on the concept map only, which of the following is most likely to be true of microbial metabolism?
1 glucose : 36 fewer ATP molecules
A new antibiotic is produced that inhibits the synthesis of acetyl-CoA and the electron transport chain in bacteria. For each glucose molecule that is metabolized, how many fewer ATP molecules will be produced?
the electron transport chain
Which of the following processes directly produce the most ATP?
the metabolism of glucose is of central importance to all living organsims and is performed in almost every cell
Glycolysis overview
constantly in living cells
glucose is one of the major energy sources in living systems … glucose is made and broken down
glycolysis — sugar splitting
the metabolic pathway for the breakdown of glucose
its disoverers
glycolysis is sometimes called the Endenmayer-hauf pathway after
uses 2 molecules of ATP to phosphorolate glucose –> easier to break apart in two 3C molecules
1. prepratory stage
1. prepratory stage
2. energy conservation stage
2. energy conservation stage
glycolysis consist of 2 main phases
4 ATP and 2 NADH molecules are produced along with 2 pyruvic acid molecules
2. energy conservation stage
the energy found in glucose has been converted to a net of 2 ATP molecules and 2 NADH molecules
at the end of glycolysis
ATP makes it easier to break apart glucose into two three-carbon molecules.
Why is ATP required for glycolysis?
sugar splitting
Glycolysis literally means
Two
1 glucose : 2 net ATP
How many net ATPs can be made from one molecule of glucose in glycolysis?
Pyruvic acid
What carbon molecules remain at the end of glycolysis?
Glycolysis is also called the Embden-Meyerhof pathway.
Which of the following statements about glycolysis is true?
the difference in charge across the plasma membrane with protons outside the membrane
The proton motive force (PMF) is driven by __________.
The terminal electron acceptor in anaerobic respiration is not oxygen.
How is anaerobic respiration different from aerobic respiration?
so that they can transport NADH out of the cell to the periplasm
the following statement is NOT a reason why electron transport chains are found in membranes
So that electron carriers can:
– orient within the membrane such that protons are passed from one side of the membrane to the other
– arrange to alternate with electron-plus-proton carriers in the chain
– efficiently pass electrons in sequence from the carriers with the more negative reduction potentials to those with the more positive reduction potentials
– orient within the membrane such that protons are passed from one side of the membrane to the other
– arrange to alternate with electron-plus-proton carriers in the chain
– efficiently pass electrons in sequence from the carriers with the more negative reduction potentials to those with the more positive reduction potentials
The following statements are reasons why electron transport chains are found in membranes.
Chemical reaction general form
AB –> A + B
AB –> A + B
The reactant molecule AB must require enough energy to disrupt its stable electron configuration so that its electron can re-arrange to form A and B
enzymes overview
enzymes accomplish this by lowering the activation energy of the reaction
— making it easier for the reactants to acquire the activation energy required to produce products
in living cells, enzymes serve as biological catalyst speeding up reactions
Enzymes decrease the amount of activation energy required for chemical reactions to occur.
Why are enzymes important to biological systems?
Krebs Cycle or Citric Acid Cycle is one of the 3 stages of cell respiration
during respiration cells completely oxidize metabolites to carbon dioxide and water to obtain chemical energy
reaction without enzyme AB –> A + B
(activation energy without enzyme) –> products A — B
(activation energy without enzyme) –> products A — B
this energy barrier is called the activation energy of the reaction
Energy is required to disrupt a substrate’s stable electron configuration.
Why do all enzymatic reactions need activation energy?
Enzymes speed up the chemical reactions in living cells.
What is meant by the statement “Enzymes are biological catalysts”?
cannot enter the Kreb cycle directly, something must happen first.
pyruvic acid generted by glycolysis
1. must be decarboxolated by the “the bridge” or transition step
2. one carbon atom is removed from pyruvic acid forming acetate
3. then attached to co-enzyme A
which is then called acetyl – CoA
4. acetyl CoA- can then enter the Kreb cycle
5.
2. one carbon atom is removed from pyruvic acid forming acetate
3. then attached to co-enzyme A
which is then called acetyl – CoA
4. acetyl CoA- can then enter the Kreb cycle
5.
pyruvic acid generted by glycolysis
the energy is released in the form of the electron carriers, NADH and FADH2 and the energy carrier, guanasine tri-phosphate GTP
Kreb Cycles carefully choreographed that efficiently extracts the energy in the pyruciv molecule in 8 enzymatic steps –>
a single molecule of pyruvic acid to generate, 15 ATP
ultimately, during one pass through the bridge step and Kreb cycle, enough energy is extracted from
enough energy is extracted in a single molecule of pyruvic acid to generate, 15 ATP
What occurs at the bridge step?
Four
Based on the animation, how many electron carriers are reduced in the Krebs cycle only?
An energy carrier
What is the function of GTP?
They are oxidized completely to carbon dioxide and water.
What is the fate of metabolites during respiration?
function only in a limited set of enzymes and cofactors
Trace elements are found in bacterial cells in very small amounts because they __________.
Pentose sugars are needed for nucleic acid synthesis.
Since glucose, a hexose, is the major source of energy for most prokaryotes, why would they need to have pentose sugars available?
You only want to determine the cell wall type, not any biochemical characteristics.
Explain why you would use selective media instead of differential media to grow an organism.
reducing the rate of a reaction to allow for better control
The role of an enzyme includes all EXCEPT which of the following?
1. straining chemical bonds in a substrate so that they break easier
2. lowering the activation energy of a reaction
3. binding only one specific substrate to the enzyme active site
2. lowering the activation energy of a reaction
3. binding only one specific substrate to the enzyme active site
The role of an enzyme includes
metabolism
as organisms live and grow, they are constantly in the process of making and breaking bonds and molecules
the sum of all chemical reactions that take place in a cell/organism
metabolism
anabolism
metabolism includes catabolism, and
breaks down complex molecules into simpler molecules, while harvesting their energy and storing it…usually in the form of ATP
catabolism — energy drives anabolic processes
carbs, lipids, proteins, DNA and RNA
complex molecules include
processes that build more complex molecules, from simpler molecules
anabolism
fatty acids, amino acids, sugars, nucleotides
simple molecules include
at each step, some of the available energy is lost into the environment at heat
neither catabolism, nor anabolim is completely efficient
is given off as heat.
In metabolism, energy that is not used
anabolism
The reactions involved in producing larger compounds from smaller compounds is called
Catabolic reactions
Where does the energy required for anabolic reactions come from?
is an example of anabolism.
The use of amino acids to make proteins
glucose
Which of the following would NOT be required to grow an autotroph?
water, trace elements, potassium phosphate
required to grow an autotroph?
The amount of ATP would be reduced from a total of 38 ATP to 14 ATP.
If the citric acid cycle was interrupted after the reaction that forms citrate, predict how this would affect the total amount of ATP generated per glucose molecule.
oxidize NADH so that NAD+ can be reused again in glycolysis
Fermentation occurs when there is no usable external electron acceptor (like O2) available for respiration. The fermentation products are made following glycolysis as a result of reactions that __________.
1. enzyme active site is filled by substrate
2. enzyme-subtrate complex forms
3. catalytic cycle is ready to begin again
4. the bond in the substrate is strained
5. release of products
2. enzyme-subtrate complex forms
3. catalytic cycle is ready to begin again
4. the bond in the substrate is strained
5. release of products
how enzymes facilitate chemical reactions.
http://media.pearsoncmg.com/bc/bc_0media_micro/conceptmaps/05/index.html
Both organisms would grow equally well.
In microbiology lab,
-three different culture plates: one general purpose plate, one selective media plate, and one differential media plate.
– forget to label the different plates, so you do not know which is which
– To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria.
– Which of the following results would indicate the plate you used was the general purpose media?
-three different culture plates: one general purpose plate, one selective media plate, and one differential media plate.
– forget to label the different plates, so you do not know which is which
– To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria.
– Which of the following results would indicate the plate you used was the general purpose media?
differential media
In microbiology lab,
– three different culture plates: one general purpose plate, one selective media plate, and one differential media plate.
-forget to label the different plates
– three different culture plates: one general purpose plate, one selective media plate, and one differential media plate.
-forget to label the different plates
– To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria.
-After inoculation, you see that a particular plate has allowed both organisms to grow, but one has changed color.
-Which plate do you think this is?
enrichment media
Which of the following types of culture media would best be used by a veterinarian to grow any bacteria in a blood sample?
inhibit the growth of certain bacteria
Which of the following would you expect to be a function of MacConkey agar? Mark all that apply.
Step 1. acetyl CoA donates the acetly group to oxaloaccetic acid –> citric acid
** the high energy bond acetyl group and CoA makes the acetly group to oxaloaccetic acid possible
** the high energy bond acetyl group and CoA makes the acetly group to oxaloaccetic acid possible
Krebs Cycles/Citric Acid Cycle
Step 1
Step 2. citric acid is rearranged to form iso-citric acid
* during this reaction, water is removed from 1C atom of citric acid and then added back to the adjacent carbon atom
* this re-arrangement is necessary to prepare the molecule for 2 consecutive de-carboxolation steps
* which both generate usable energy
Krebs Cycles/Citric Acid Cycle
Step 2
Step 3 — the iso-citric acid is oxidized and de-carboxolated to produce alpha-ketoglutaric acid
* –> free energy is used to reduce an NAD molecule to generate a NADH molecule
* –> NADH generates 3 ATP through oxadated phosphorolation
Krebs Cycles/Citric Acid Cycle
Step 3
Step 4 — alpha-ketoglutaric acid loses another carbon atom in the form of CO2
* loss of CO2 –> large release of energy –> another NADH molecule is generated from NAD
* the remaining 4C succinyl group is attached to CoA producing succinyl CoA
* allows even more energy to be extracted from the succinyl molecule
Krebs Cycles/Citric Acid Cycle
Step 4
Step 5 — water reacts with succinyl CoA
* release CoA, and producing succinyl acid
* high energy bond breakage release energy which is coupled to the phosphorolation of a guancine-diphosphate molecule –> guancine tri-phosphate (GTP)
* GTP carries the same amount of energy as an ATP molecule, so it can be used to produce an ATP molecule
* the CoA can be recycled to the previous step, to react with alpha-ketoglutaric acid s
Krebs Cycles/Citric Acid Cycle
Step 5
Step 6 — involves an oxidation reaction in which succinic acid loses 2H atoms –> fumaric acid
* FAD gains the 2H reducing FAD to FADH2
* FADH2 can produce 2 ATP molecules in the oxidative phosphorolation process
Krebs Cycles/Citric Acid Cycle
Step 6
Step 7 — fumaric acid is hydrated to form malic acid
* this step does not produce energy in itself but, prepares the intermediate for the next step
Krebs Cycles/Citric Acid Cycle
Step 7
Step 8 — a full cycle is reached
* malic acid is oxidized to regenerate oxaloacetic acid ( one of the reactants from Step 1)
* at the same time a molecule of NAD is reduced to NADH
Krebs Cycles/Citric Acid Cycle
Step 8
Oxaloacetic acid
Which of the following is needed as a reactant for the first step of the citric acid cycle?
Succinyl CoA
Where does the energy come from to power the formation of GTP?
The third and fourth steps
Which step involves the release of carbon dioxide?
Three 1NADH: 3ATP
How many molecules of ATP can be generated from one molecule of NADH?
The second and seventh steps
Which step(s) of the Krebs cycle does (do) not produce any usable energy?
The reaction is not balanced, so you cannot calculate the change in free energy.
To calculate the free energy (ΔG0′) of a reaction, you can subtract the free energies of formation (Gf0) of the reactants from those of the products. Given the following data, what will be true of this reaction? C6H12O6 + O2 → CO2 + H2O Gf0 : -917.3 0 -394.4 -237.2
