Lecture #7 Flashcards
What is metabolism
The sum of all chemical reactions that occur within an organism
What are the two classes metabolism is divided into?
- Catabolism
2. Anabolism
What is a catabolic reaction vs a anabolic reaction?
Catabolic- Reactions that generate energy
Anabolic- Reactions that require energy
How does a catabolic reaction work?
Breaking down a complex organic compound into simpler ones
What is an example of a catabolic reaction?
Proteins are broken down into their amino acid components releasing energy
How does an anabolic reaction work? Or what does it do?
It is the biosynthesis or building of complex organic molecules from simpler ones
What is an example of an anabolic reaction?
Amino acids that are used to build proteins, consuming energy
What is ATP
Energy stored in the form of Adenosine Tri-Phosphate
What allows Adenosine Tri-Phosphate to be so high in energy?
The bonds between each of the 3 phosphate groups are very high in energy
How is Adenosine Tri-Phosphate’s energy used?
When the bonds are broken, lots of energy is released
What is ATP used for?
A driving source for other chemical reactions
What type of metabolic reaction generates ATP? Which consume?
Catabolic- generate
Anabolic- consume
What is oxidation reduction reactions called?
Redox reaction
What is oxidation? What is reduction?
Oxi- loss of an electron by a molecule
Reduction- the gaining of an electron by a molecule
NAD+ reduction reaction=?
NADH
Oxidation and Reduction always occur_______. This is called__________?
Simultaneously
Called a redox reaction
What is NAD
Nicotinamide Adenine Dinucleotide
The oxidized form of NAD is…?
NAD+
The reduced from of NAD is…?
NADH and H+
What does NAD do?
Acts as an electron carrier
How does NADH work as an electron career?
2 electrons are removed from the donor molecule and added to the recipient molecule as well as 2 protons transferred
What is the collision theory?
Since atoms and molecules are in constant random motion, collisions occur in between the atoms and molecules
What do the collisions of atoms and molecules result in?
Chemical bonds being broken into reactants and formed into products
What is activation energy?
The minimum amount of energy needed for a reaction to occur
What are 3 things that can be done to decrease the activation energy needed for a reaction to occur?
- Increase temperature
- Increase the pressure
- Add an enzyme
Enzymes function as______ to lower the activation energy of a particular reaction
Catalysts
Can enzymes be reused after a reaction?
Yes because they are not altered
A specific enzyme catalyzes how many reactions?
Only one reaction
How does an enzyme lower the activation energy needed?
By positioning the substrate such that there is a greater probability that the reaction will take place
How much faster does an enzyme make a reaction occur?
10 billion times
What is carbohydrate catabolism?
The breakdown of carbohydrates in order to release energy
What is the most common carb used by cells for energy
Glucose
What two processes can be used to catabolize glucose?
- Cellular respiration
2. Fermentation
Does cellular respiration need oxygen or not to catabolize glucose?
Occurs when oxygen is present
Which is more efficient for the catabolism of glucose: Cellular respiration or fermentation?
Cellular respiration? (eating the whole apple)
How many ATP are released during cellular respiration?
About 32
How many ATP are released during fermentation?
about 2
What are the 3 main stages of cellular respiration
- Glycolysis
Intermediate step - Krebs cycle
- Electron Transport Chain
Where does glycolysis occur?
In the cytoplasm of any living cell
How many reactions occur during glycolysis?
10
What is the simple version of what happens in glycolysis?
Splitting of a sugar (glucose) into two pyruvic acid molecules
Does glycolysis need oxygen or not?
Can occur in the presence or absence of it
How much energy is released during glycolysis?
2 ATP, 2 NADH
What is the intermediate stage of cellular respiration?
2 molecules of pyruvic acid are prepared for the entry into the krebs cycle
What occurs in the intermediate stage of cellular respiration?
- One CO2 is removed from each pyruvate (2 CO2 total)
2. A COA group is added to each of the two newly formed carbon sugars
What does the addition of COA to the pyruvate molecules do?
Forms 2 molecules of acetyl COA from the two pyruvate
What is gets removed aside from CO2 during the intermediate step?
2 NADH
What is removed during the intermediate stage?
CO2
What is added at the end of the intermediate stage?
CoA group is added to each of the newly formed carbon sugars
What is broken down during the krebs cycle?
2 molecules of acetyl CoA are broken down into 4CO2 (carbon dioxide)
What are all the things formed by the end of the krebs cycle?
2ATP, 6 NADHand 2 FADH
Where does the Krebs cycle take place in a eukaryotic and a bacterial cell
In the cytoplasm of the bacterial cell and in the mitochondria of eukaryotes
Does the krebs cycle require oxygen?
Yes
Where does the electron transport chain occur in?
The bacterial membrane
What does the electron transport chain do?
Transports electrons from NADH through a series of electron carriers
What is created at the end the transport chain?
H2O
How much ATP is produced during the electron transport chain?
2-3 ATP for each NADH that pass through the chain
Does fermentation need oxygen?
NO
What produces more energy: Aerobic respiration or Fermentation?
Aerobic Respiration
What steps of aerobic respiration are not present in fermentation?
Krebs cycle and electron transport chain
How many ATP are produced in fermentation per 1 glucose?
2 ATP
What are the two main types of fermentation?
- Alcohol Fermentation
2. Lactic Acid Fermentation
What is alcohol fermentation carried out by?
yeast/fungi and some bacteria
What are the waste products of fermentation?
Ethanol and Carbon Dioxide
How many ATP are produced during alcohol fermentation?
2
During Lactic Acid Fermentation, what is converted into lactic acid?
Pyruvic Acid
What Lactic Acid Fermentation carried out by?
Many bacteria
Ex. Lactobacillus Acidophilus
What can lactic acid fermentation cause? What can it also be used for?
Food spoilage, food production
How many ATP are produced in lactic acid fermentation?
2 ATP
What is the primary energy source used by bacteria? What are 3 others that are used?
Primary- glucose
Others- Carbs, lipids and proteins
When a carbohydrate is used as an energy source, what happens (how is it used)?
- Polysaccharides such as starch are broken down into component sugars
- The component sugars are then converted to glucose
- The glucose then enters the metabolic cycle beginning with glycolysis
When a lipid is used as an energy source, what happens (how is it used)?
- Lipids are broken down into its components (Fatty acids and glycerol) by the enzyme lipase
- The components then enter the metabolic cycle via glycolysis or Krebs cycle
When a protein is used as an energy source, what happens (how is it used)?
- The protein is broken down into its component amino acids by the enzyme proteases
- The amino acids then enter the metabolic cycle via glycolysis or krebs cycle
Anabolism also means
Biosynthesis (the production of complex molecules inside an organism or cell)
What are precursor metabolites?
The components of glycolysis and the krebs cycle that start as the starting point for the production of amino acids, lipids and nucleotides
The components of glycolysis and krebs cycle usually serve as the starting point for what?
Production of amino acids, lipids and nucleotides
Organisms can be classified based on their nutritional needs which are…?
- Source of Energy
2. Source of Carbon
Most medically relevant bacteria are….?
chemoheterotrophs
What is a photoautotroph?
An organism that uses light energy to produce ATP and CO2 as their carbon source in photosynthesis
What is a photoheterotroph?
An organism that uses light energy to produce ATP and use organic carbon (obtained from food)
Which group of photo organisms includes some bacteria?
Photoheterotrophs
What is a chemoautotroph?
An organism that uses chemical reactions to obtain energy and CO2 as a carbon source
The chemical reactions involved for chemoautotrophs reduce what type of inorganic molecules?
H2, H2S and CO
What are chemoautotrophs?
These organisms use chemical reactions to obtain energy and organic molecules as their source of carbon
What category of metabolic diversity to be fall under?
Chemoautotrophs
animals, fungi and protozoa as fall into this category
