Exam 2 Study Guide Flashcards
Energy
The ability to do work. The ability to move matter.
2 forms of energy
- Potential
2. Kinetic
Eg of Potential energy
Energy stored in the covalent bonds of food
Gravity
Eg of Kinetic Energy
Light
Sound
Movement
Muscle contraction
Potential Energy
stored energy available to do work
Kinetic energy
Energy being used to do work ( any moving object)
calories
units used to measure energy
It is the amount of energy necessary to raise the temperature of 1 gram of water 1 degree
The laws of thermodynamics
1st law = The law of energy conservation
Energy is neither created or destroyed
2nd Energy transformation is inefficient. With each transformation some energy is lost as heat.
Entropy
The measuree of the randomness of molecular movements that results in heat
Metabolism
encompasses all the chemical reactions in the cell
what does metabolism involve
. building new molecules
. breaking down molecules
. each reaction rearranges atoms into new compounds
. each reaction either releases or absorbs energy
Endergonic Reaction
Requires input of energy to proceed
reactants ( lesser)= products (greater)
eg. water+ carbon dioxide = glucose + oxygen(Photosynthesis
Exergonic reaction
Releases energy
reactants ( greater) = Products less
eg
Glucose + oxygen = Water carbon dioxide Atp
Chemical equilibrium
Chemical reaction goes in both direction at the same rate.
Why are cells not in chemical equilibrium
It stops the cells metabolic process from moving forward
May force the cell to extend more energy to do the same work
Metabolic Pathway
A series of chemical reaction in which the product of one reaction is quickly used up by the next.
Oxidization
loss of electrons from a molecule atom or ion CR Exergonic energy is released breakdown of molecules
Reduction
the gain of electron Potosynthesis Endergonic energy is required build up of molecules
Electron Transport Chain
A series of protein that transfer energy rich electrons from one protein to the next. With each transfer a small amount of energy is released which the cell uses to carry out other reactions
ATP
a nucleotide that stores released energy in the covalent bonds of its phosphorus group.
It holds energy released in exergonic reactions long enough to power endergonic reactions
The chemical structure of Atp
nitrogenous base=adenine
5 carbon sugar= ribose
3 phosphate groups
(Triphosphate + adenisone)
Phosporylation
The coupling transaction of arp and tap transferring one phosphate group to another molecule.
Atp is exergonic hydrolysised to create energy and a phosphate.
energy is temporarily stored by adding a phosphate along with energy to get atp and water
The coupled reactions of ADP and ATP
ATP + H20 ADP + P + ENERGY
Enzymes
A protein that catalyses a chemical reaction by lowering the energy activation without being consumed
what environmental conditions affect their activity
high salt content
drugs (internal or external)
temperatue
ph
How do substrates bond to active sites of enzymes
Substrates fit like puzzles to active sites
cofactors
are inorganic and organic helpers of enzymes that MUST be present for the enzyme to work.
coenzymes
organic cofactors e.g., water soluble vitamins
Negative feed back
a way that cells control reaction rates in cells. with high product accumulation a product bonds with the enzyme that formulated it to prevent further production
2 types of Negative feedback
- competive inhibition
2. non competitive inhibition
non competitive inhibition
The product binds with the enzyme at a location other that the active site changing the shape.
competive inhibition
The product binds to the active site preventing the substrate from binding with it.
Concentration gradient
A solute is more concentrated in one region than in a neighboring region
Why is Concentration gradient important
Because all forms of transport across membranes involve gradients
Passive transport
a substance moves across a membrane without the expenditure of energy. All forms of passive transport invoke diffusion
Diffussion
an example of passive diffusion.
The spontaneous movement of substance from an area of more concentration to area with low concentration. does not require energy
Simple diffusion
substances to which the the membrane is permeable moves across the membrane without the assistance of membrane protein. Lipids, small, non polar molecules (o2,Co2)
osmosis
The simple diffusion of water across a selectively permeable membrane
Facillitated diffusion
Substances to which the membrane is NOT PERMEABLE move across the membrane with the assistance of membrane proteins
Ions, polar molecules, molecules like glucose
3 Types of Passive transport
simple diffusion
osmosis
Facilitated diffusion
3 Types of transport mechanisms
passive
active
vesicles
Active Transport
a cell uses transport proteins to move a substance against its concentration gradient. It is used to create or maintain the concentration gradient
