Unit 2: Chapter 7 Bacterial Metabolism Flashcards
What is catabolism?
provides energy and the building blocks (e.g amino acids)
Breaks things down
Catabolic reactions are what type of reactions?
exergoinc
Release energy
What is anabolism?
uses energy and building block to build large molcules
builds things up
Anabolic reactions are what type of reactions?
endergonic
Utilize energy
An example of foods and them using canabolism and anabolism
Just a picture
What is the collison theory?
In order for a reaction to occur molecules have to collide and break in certian ways in order to break the bond
For the collison theory to occur, what do we need to happen?
3 things
- Frequent collison
- Collison should be energetic
- Orientation of the collison
What is activation energy?
The minimum energy required to start a chemical reaction
What helps lower the activation energy?
Enzymes
Allow it so that the minimum energy needed for the reaction to take place is lowered
What are enzymes made out of?
Amino acids
They are proteins
T or F: Enzymes are all the same shape
False; Enzymes all have unique shapes
What do enzymes have that help with binding substrates?
Active sites
What do the active sights help take care of in regards to the collison thoery?
Frequent collison and orientation
Are enzymes highly specific?
Yes; enzymes are highly specific in terms of what substrate they act upon
Advantages of the enzymes and substrates tight bond
It allows for it to bind tightly enough to where it puts stress on the bond and gives it that enegry
Many enzymes will end in _________
-ase
What are cofactors and coenzymes?
An additional non-protein molecule that is needed by many enzymes to help the reaction
What are coenzymes?
organic molecules such as vitamins
What do coenzymes function as?
They function as intremediate carriers of electrons or functional groups that are transferred during a chemical reaction
What are cofactors?
inorganic substances such as metal ions
Enzyme Mechanism
Name 4 steps
Picture with the steps of a substrate binding to an enzyme
ATP
Just a picture
ATP and ADP are constantly being ________
recycled
ATP is genereted by
the phosphorylation of ADP
What occurs in substrate-level phosphorylation?
An enzyme transfers a phosphate group from a substrate molecule to ADP which then forms ATP
What two metabolism cycles use substrate-level phosphorylation?
glycolysis and citric acid cycle
T or F: a large amount of ATP is made via substrate-level phosphorylation
False; small amounts of ATP are from in glycolysis and the citric acid cycle by substrate-level phosphorylation
What is oxidative phosphorylation?
- This makes the most ATP
- Involved the electron transport chain (ETC) and oxidation-reduction of electron carriers of ETC
What does oxidative phosphorylation require?
an adequate supply of terminal electron acceptor
Oxidation
removal of electrons
Reduction
gain of electrons
Redox reaction
an oxidation reaction paired with reduction reaction
In biological systems, the elctrons are often associated with
hydrogen atoms
Oxidation-Reduction
Just a picture to help
What are the cellular respiration steps?
Glucose (c6h12o6) + Oxygen (o2) —-> Glycolysis —-> Krebs Cycle —-> Electron Transport Chain —-> Carbon Dioxide (co2) + Water (h2o) + ATP
Carbohydrate Catabolism
Cellular Respiration Analogy
Just a picture
Where does glycolysis occur?
In the cytoplasm in both eukaryotes and prokaryotes
Does glycolysis require oxygen?
No; glycolysis is an anerobic process aka it does not require oxygen
What are the 3 stages in glycolysis?
- Activation stage or investment stage (reactions 1-3)
- Enegry used in this stage - Cleavage stage (reaction 4)
- Splitting - Harvest stage or return stage (reactions 6-11)
- NADH is produced
- ATP is produced
Glycolysis Steps
Just a picture
Need to know whats in the picture
Substrate: Glucose
Product: 2 pyruvate
ATP used: 2
ATP produced: 4
Net ATP: 2
NADH: 2
FADH: 0
What is the intermediate step?
When pyruvate (pyruvic acid) turns into acetyl-coA.
Substrate: 2 pyruvate
Products: 2 CO2 and 2 acetyl coA
ATP used: 0
ATP produced: 0
ATP Yeild: 0
NADH: 2
FADH: 0
Where does the intermediate step occur in eukaryotes?
in the matrix of the mitochondria
Where does the intermediate step occur in prokaryotes?
in the cytoplasm
Where does the krebs cycle occur in eukaroytes?
in the matrix of the mitochondria
Where does the krebs cycle occur in prokaryotes?
in the cytoplasm
Krebs Steps
Need to know whats in the picture
Just a picture
Substrate: 2 Acetyl coA
Product: 4 CO2
ATP used: 0
ATP produced: 2
ATP Yeild: 2
NADH: 6
FADH: 2
The electron transport chain ins comprised of a series of multiprotein complexes called
electron carriers
The carriers in the ETC alternate reduced and oxidized states as they ____ and ____ electrons
accept and donate
What happens to electrons as they are passed down the chain?
they drop in energy
What is the terminal electron accepter in the ETC?
O2
What does the terminal electron accepter (O2) form?
H2O
What does the electron transfer in ETC cause proteins to do?
It causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space
What happens when H+ moves back across the membrane?
it passes through the protein complex, ATP synthase
How does ATP synthase make ATP?
It uses the exergonic flow of H+ to drive phosphorylation of ATP
Where does the electron transport chain take place in eukaryotes?
in the inner membrane of the mitochondria
Where does the electron transport chain take place in prokaryotes?
in the inner membrane
What is chemiosmosis?
The use of energy in a H+ gradient to drive cellular work
What is the proton motive force?
The H+ gradient
Electron Transport Chain in picture form
Just a picture
There is a higher concentration of protons on the outside of the cell
How much ATP does one NADH make?
3 ATP
How much ATP does 1 FADH make?
2 ATP
Total number of ATP made broken down
Theoretically
Why don’t we always make the full 38 ATP’s in cellular respiration?
Because we have other processes going on. The proton motive force is also required to move flagella, maintain overall charge of cell, and help with nutrient uptake.
Anaerobic Respiration
No oxygen required
Some bacteria can use alternative terminal electron acceptors to complete respiration, instead of oxygen
Because anaerobic respiration can’t pump as many protons out, what happens?
It yields less energy than aerobic respiration
T or F: anaerobes grow faster than aerobes
False; anaerobes grow slower than aerobes
Little chart
What is fermentation?
The incomplete oxidation of sugars in the absence of oxygen
T or F; Fermentation uses krebs and the electron transport chain
False; fermentation does not use either krebs or the electron transport chain
What does fermentation use as the terminal electron acceptor?
they do not have a terminal electron acceptor
The essential function of the second stage of fermentation is to ensure a steady supply of
NAD
What are the two types of fermentation?
- Lactic acid fermentation which produces lactic acid
- Alcohol fermentation which produces ethanol + CO2
Where does lactic acid fermentation occur?
In the muscle
Where does alcohol fermentation occur?
in the cytosol of the cell
Lactic Acid and Alcohol Fermentation
Just a picture
Build up of NADH so need to regenerate NAD+ through oxidation
Where is ATP synthase located?
in the inner membrane of the mitochondria
The fate of pyruvate at the end of glycolysis depends on
whether there is a terminal electron acceptor
1. Terminal electron acceptor? ETC
2. No terminal electron acceptor? Fermentation
What is lithotrophy?
An inorganic, reduced, molecule serves as the electron donor instead og an organic compound
What are som examples of inorganic molecules?
- Ferrous Iron
- Ammonium Ion
- Hydrogen Gas
Amphilibolic Pathways
These are pathways that can be used to build things up and break things down (catabolism and anabolism)
Interrealtionship of catabolic pathways
Just a picture
ATP is formed in what type of reactions?
Anabolic or catabolic?
Catabolic
ADP is formed in what type of reactions?
Anabolic or catabolic?
Anabolic
NAD+ —> NADH
Oxidized or reduced?
Reduced
gain electron (H)
NADH —> NAD+
Oxidized or reduced?
Oxidized
Lose electron (H)
What is true in regards to the ETC and fermentation?
They both regenerate NAD+
Can glycolysis and krebs proceed without NAD+?
No; NAD+ must be present in order for glycolysis and krebs to proceed