Unit 3 Flashcards
What is metabolism?
Metabolism is all of the chemical reactions in an organism.
What are metabolic pathways?
Metabolic pathways are series of chemical reactions that either build complex molecules or break down complex molecules.
What are the two types of metabolic pathways?
The two types of metabolic pathways are catabolic pathways and anabolic pathways.
What are catabolic pathways?
Catabolic pathways are pathways that release energy breaking down complex molecules into simpler compounds.
What are anabolic pathways?
Anabolic pathways are pathways that consume energy to build complicated molecules for simpler compounds.
What is energy?
Energy is the ability to do work.
Why do organisms need energy?
Organisms need energy to survive and function.
What will happen to an organism if there is a loss in energy flow?
If an organism has a loss in energy flow it results in death.
What is kinetic energy?
Kinetic energy is energy associated with motion.
What is thermal energy?
Thermal energy is energy associated with the movement of atoms or molecules.
What is potential energy?
Potential energy is stored energy.
What is chemical energy?
Chemical energy is potential energy available for release in a chemical reaction.
What is thermodynamics?
Thermodynamics is the study of energy transformations in matter.
What is the 1st law of thermodynamics?
The 1st law of thermodynamics is energy cannot be created or destroyed but energy can be transferred or transformed.
What is the 2nd law of thermodynamics?
The second law of thermodynamics is that energy transformation increases the entropy (disorder) of the universe. During energy transfers or transformations, some energy is unusable and often lost as heat.
What is the concept of free energy used for?
The concept of free energy is used to determine the likelihood of reactions in organisms or if the reactions are energetically. It determines whether a reactions occurs spontaneously.
Based on free energy, what are the two things chemical reactions be classified as?
The two things chemical reactions can be classified as are exergonic reactions or endergonic reactions.
What are exergonic reactions?
Exergonic reactions are reactions that release energy.
(reaction is spontaneous)
ex. cellular respiration
What are endergonic reactions?
Endergonic reactions are reactions that absorb energy.
(reaction is not spontaneous and absorbs free energy)
ex. photosynthesis
How does material flow in living cells?
Living cells have a constant flow of materials in and out of the membrane, and are not at equilibrium.
What are the three kinds of work cells perform?
The three types of work that cells perform are mechanical, transport, and chemical.
What is mechanical work done by cells?
Mechanical work done by cells is movement.
What is transport work done by cells?
Transport work done by cells is pumping substances across membranes against spontaneous movement.
What is chemical work done by cells?
Chemical work done by cells is synthesis of molecules.
What is adenosine triphosphate?
Also known as ATP, adenosine triphosphate is a molecule that organisms use as a source of energy to perform work.
How does ATP power cellular work?
ATP couples exergonic reactions to endergonic reactions to power cellular work.
What is phosphorylation?
Phosphorylation is when the released phosphate moves to another molecule to give energy .
How can ATP be regenerated?
ADP can be regenerated to ATP via the ATP cycle.
What do enzymes help do in cells?
Enzymes help cells to speed up reactions and break things down.
What are enzymes?
Enzymes are macromolecules that catalyze (speed up) reactions by lowering the activation energy. They are a type of protein and are not consumes by the reaction.
What do enzymes act on?
Enzymes act on a reactant called a substrate.
What is an active site in an enzyme structure?
An active site is an area for substrates to bind.
What is an induced fit in the enzyme structure?
An induced fit is when an enzyme will change the shape of their active site to allow the substrate to bind better.
What happens during enzyme catabolism?
During enzyme catabolism an enzyme helps break down complex molecules.
What happens during enzyme anabolism?
During enzyme anabolism an enzyme helps build complex molecules.
What can affect the efficiency of enzymes?
The efficiency of enzymes can be affected by temperature, pH, and chemicals.
What does a change in shape mean for enzymes?
A change in shape means a change in function for enzymes.
What are optimal conditions for enzymes?
Optimal conditions are the conditions (temperature & pH) that allow enzymes to function optimally and at their best.
What are enzyme cofactors?
Cofactors are non protein molecules that assist enzyme function. They can bound loosely or tightly.
What is a holoenzyme?
A holoenzyme is an enzyme with the cofactor attached.
What are coenzymes?
Coenzymes are organic cofactors.
What are enzyme inhibitors?
Enzyme inhibitors reduce the activity of specific enzymes and they can be permanent or reversible.
What does it mean when an enzyme inhibitor is permanent?
A permanent inhibitor binds with covalent bonds.
What does it mean when an enzyme inhibitor is reversible?
A reversible inhibitor binds with weak interactions.
What are competitive inhibitors?
Competitive inhibitors reduce enzyme activity by blocking substrate from binding to the active site.
How can competitive inhibitors be reversed?
Competitive inhibitors can be revered with increased substrate concentrations.
What is a noncompetitive inhibitor?
Noncompetitive inhibitors bind to an area other than the active site (allosteric site) which changes the shape of the active site preventing substrates from binding.
How does a cell regulate its metabolic pathways?
A cell must be able to regulate its metabolic pathways by controlling where and when enzymes are active and switch genes that code for enzymes off or on.
What are the two binding sites that allosteric enzymes have?
Allosteric enzymes have two binding sites that are 1 active site and 1 allosteric site (regulatory site; site other than the active site).
What is allosteric regulation?
Allosteric regulation is when molecules bind (noncovalent interactions) to an allosteric site which changes the shape and function of the active site. This may result in inhabitation (by an inhibitor) or stimulation (by an activator) of enzymes activity.
What is an allosteric activator?
An allosteric activator is an allosteric substance that bind to an allosteric site and stabilizes the shape of the enzyme so that the active site remains open.
What is an allosteric inhibitor?
An allosteric inhibitor is an allosteric substance that binds to an allosteric site and stabiles the enzyme shape so that the active sites are closed (inactive form).
What is cooperativity?
Cooperativity is when an allosteric substrate binds to one active site (on an enzyme with more than one active site) which stabilizes the active form. This is considered allosteric regulation since binding at one site changes to shape of other sites.
What is photosynthesis?
Photosynthesis is the conversion of light energy to chemical energy.
What are autotrophs?
Autotrophs are organisms that produce their own food (organic molecules) from simple substances in their surroundings.
What are heterotrophs?
Heterotrophs are organisms unable to make their own food so they live off of other organisms.
Where did photosynthesis first evolve?
Photosynthesis first evolved in prokaryotic organisms.
What is cyanobacteria?
Cyanobacteria is early prokaryotes capable of photosynthesis and oxygenated the atmosphere of early earth.
Where did the foundation of eukaryotic photosynthesis come from?
Prokaryotic photosynthetic pathways were the foundation of eukaryotic photosynthesis.
What is the primary location of photosynthesis is most plants?
Leaves are the primary location of photosynthesis in most plants.
What is a chloroplast?
A chloroplast is the organelle for the location photosynthesis.
Where are chloroplast found?
Chloroplast are found in the mesophyll.
What is the mesophyll?
The mesophyll is the cell that makes up the interior tissue of the leaf.
What are stomata?
Stomata are pores in leaves that allow CO2 in and O2 out.
What surrounds chloroplasts?
Chloroplasts are surrounded by a double membrane?