Chapter 4 The Energy Of Life Flashcards
What are the two types of energy and their function?
Potential- stored energy
Kinetic- energy being used to do work
What is energy?
Ability to do work; move matter.
What are the two laws of energy?
First law- energy is never created or destroyed, but, converted into other forms.
Second law- energy transformations are inefficient (due to the loss of energy-heat-at every step that cannot be used).
What is entropy?
Randomness or disorder
What is metabolism?
Chemical reactions in cells that build new molecules and break down existing ones.
Explain anabolic.
Requires energy, builds molecules.
Exp: photosynthesis
dehydration synthesis.
Reduction
Explain catabolic.
Releases energy, breaking down molecules.
Exp: cellular respiration
Hydrolysis
Oxidation
What is oxidation-reduction?
Transfer of energized electrons from one molecule to another.
What happens with oxidation?
Loss of electron (release energy)
What happens in reduction?
Gain of electron (require energy).
What is an electron transport chain?
Proteins shuttle electrons along the ETC with energy lost at each step
What is ATP made up of?
ATP is a nucleotide:
Adenine (nitrogenous base)
Ribose (5 carbon sugar)
3 phosphate groups (neg charges)
Removing the _______ __________ ______, by hydrolysis releases the potential energy stored in ATP. the cell uses this energy to do work. This creates _____ & ______.
End most phosphate group
ADP & energy (free phosphate group)
Which organelle does ATP occur?
Mitochondria
What is coupled reaction?
Cells use ATP hydrolysis (release energy), to fuel reactions that require energy input. (Pairing)
What is an enzyme?
Organic molecule that that speeds a chemical reaction.
Most are protein, some are RNA
When ATP donates a phosphate group to a molecule, the recipient may be more likely to _____ or to ______ ______ in a useful way.
Bond
Change shape
What is a substrate?
Reactant in an enzymatic reaction.
What is the active site?
The region to which the substrate binds (the enzyme).
What is activation energy?
The amount if energy required to start a reaction.
An enzyme speeds up a Chemical reaction by…
Lowering (decreasing) the activation energy
What is one way to regulate metabolic pathways? Explain function.
Negative feedback, product of a reaction inhibits the enzyme that controls it’s formation.
What are the two ways negative feedback works?
Explain.
Noncompetitive inhibition (allosteric)- product molecule binds to the enzyme at the location other than the active site, altering the shape so the substrate can no longer bind.
Competitive inhibition- reaction product bids at the active site, preventing the substrate from binding.
Enzymes normally end with _______.
-ase
What factors affect enzyme activity?
Temp (heat), salt concentration, ph
Which of the two requires energy?
Passive or active transport
Active
What is simple diffusion?
Substance moves across membrane w/o assistance of protein or atp
What is osmosis?
Water diffusing across selective permeable membrane
What is facilitated transport?
Substance moves across membrane with assistance of protein
What is active transport?
Net movement against concentration gradient requires transport protein and energy
What are the two transport using vesicles?
Endocytosis and exocytosis
What is the difference between endocytosis and exocytosis?
Endo – membrane engulfs substance in draws into cell
Exo – vesicle fuses with the cell membrane releasing substances outside the cell
What is tonicity?
(Tone) ability of a solution to cause water movement
What is iso tonic solution?
Same concentration inside as out of cell
What happens with a hypotonic solution?
Water will diffuse into the cell and cause the cell to swell
What happens in a hypertonic solution?
Water moves outside of the cell and causes it to shrink
What are the two main forms of endocytosis? Explain both.
Pinocytosis – cell engulfs fluids and dissolved substances
Phagocytosis – cell captures and Engulfs large particles
