Topic 5 and 6 Bio
What is Metabolism?
Totality of an organism's chemical reactions
What does a metabolic pathway begin and end with?
It begins with a specific molecule and ends with a product
Is each step catalyzed by a specific enzyme?
Yes
How do Catabolic Pathways release energy?
They release energy by breaking down complex molecules into similar compounds
Describe an anabolic pathway
They consume energy to build complex molecules from simpler ones
What is an example of an anabolic pathway?
Protein synthesis from amino acids
What are bioenergetics?
The study of how organisms manage their energy resources
Kinetic energy is associated with________
Motion
Heat (thermal energy) is __________________________________________
kinetic energy associated with random movement of atoms or molecules
Potential Energy is _________________________
Energy that matter possesses because of its location or structure
Chemical Energy is _______________
Potential energy availabe released in a chemical reaction
How do spontaneous processes occur?
Without energy input and happen quickly
What is a living systems "free energy"
energy that can do work when temp and pressure and uniform, such as in a living cell
Exergonic reactions __________ free energy and is ________
release and spontaneous
Endergonic reactions ___________ free energy and is ________________
absorbs, nonspontaneous
Energy coupling in cells is mediated by ___
ATP
What is energy coupling?
Cells manage energy resources by energy coupling, or the use of a exergonic process to drive an endergonic one
What is ATP composed of?
a ribose (sugar), adenine (nitrogenous base), and three phosphate groups
How is energy released from ATP?
When the terminal phosphate bond is broken
What is a catylist?
Chemical agent that speeds up a reaction
What is an enzyme
Catalytic protein
The initial energy needed to start a chemical reaction is what
Activatio Energy
How do enzymes catalyze reactions?
By lowering the activation energy barrier
What is a substrate?
It is what an enzyme acts on
What is created when an enzyme binds to its subsrate?
Enzyme-substrate complex
What is an active site?
The region where the substrate binds to an enzyme
What does induced fit do?
Brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction
How can the active site lower EA?
Through orienting substrates correctly, straining substrate bonds, providing a favourable microenvironment, covalently bonding to a substrate
What are some factors that effect enzymes?
Temperature and pH, and certain chemicals can influence the enzyme
How does temperature and pH affect an enzyme?
It affects the shape, thus affecting the enzymes ability to function
What are cofactors?
Nonprotein enzyme helpers
What is an organic cofactor called?
An organic cofactor is alled a coenzyme
What is competative inhibition?
Inhibitors that bind to the active site
What is noncompetative inhibition?
Bind to another part of the enzyme, leading to the enzyme changing shape
What are some examples of inhibitors?
Toxins, poisons, pesticides, and antibodies
What is feedback inhibition?
When the end product of a metabolic pathway shuts down the pahway
How is feedback inhibition benefictal?
Prevents a cell from wasting chemical resources by synthesizing more product than what is needed
Enzymes need for cellular respiration are housed where?
In the mitochondria
Is the breakdown of organic molecules exergonic or endogonic?
Exogonic
What does fermentation occur without?
Oxygen
What does Aerobic respiration consume that Anaerobic respiration does not?
Oxygen
What do aerobic and anerobic respiration both yield?
ATP
Electrons from organic compounds are usually first transfered to _______, a coenzyme
NAD+, becoming NADH
Where does NADH pass electrons?
To the electron transport chain
How is energy gained from the ETC?
Oxygen pulls electrons down the chain in an energy yielding tumble, the energy yielded is used to regenerate ATP
What are the three phases of Cellular Respiration?
Glycolysis, The Citric Acid Cycle, and Oxidative phosphorylation
What does gycolysis do?
Breaks down glucose into two molcules of pyruvate
How many molecules of pyruvate are created from glycolysis?
Two
What does the citric acid cycle do?
Completes the breakdown of glucose
Where does The Citric Acid Cycle take place?
In the mitochondria
What process generates the most ATP?
Oxidative phosphorylation
What is subsrate-level phosphorylation?
The smaller amount of ATP is formed in glycolysis and the citric acid cyclr
What is glycolysis?
The splitting of sugar, breaking down glucose into 2 pyruvate molecules
Where does glycolysis occur?
In the cytoplasm
What are the two phases of Glycolysis?
Energy Investment and Energy Payoff
How much ATP is created from Glycolysis
Net increase of 2
How does pyruvate enter the mitochondria?
Through coenzyme A
What is pyruvate converted into?
Acetyl CoA
What does the Krebs cycle do?
Breaks down pyruvate to CO2
Where is the ETC located?
In the inner membrance of the mitochondrion (cristae)
What is proton-motive force?
The H+ gradient, emphasizing its capacity to do work
During CR how does energy flow?
Glucose --> NADH --> ETC --> Proton-motive force --> ATP
How many ATP are made from one glucose molecule?
32
Without Oxygen what ceases to function?
The ETC
What are the two types of fermentation
Alcohol and lactic acid fermentation
In alcohol fermentation, pyruvate is converted to what in 2 steps?
Ethanol, and releases CO2
What is formed in lactic acid fermentation?
Lactate, with no CO2 released
What are obligate anaerobes?
Carry out fermentation and cannot survive in the presence of oxygen
What are faculatative anaerobes?
Can survuve using either fermentaino or cellular respiration
beta oxidation breaks down fatty acids and yield ________
acetyl CoA
Fats are digested to ________ used in glycolysis
glycerol
How is cellular respiration regulated?
Through feedback inhibition