CHEMISTRY PART III metabolism and enzymes

what is metabolism

chemical reactions that take place inside of a cell that make an organism alive

when u break covalent bonds outside of the cell what happens to the energy

u lose the energy as heat

what happens to the energy when u break covalent bonds inside of a cell

there is a chance to capture the energy as another covalent bond

what are catabolic reactions

reactions where bonds are broken

what are anabolic reactions

reactions where bonds are built

hydrolisis is a type of ___ reaction

catabolic

dehydration synthesis are a type of ___ reaction

anabolic

where does a monomer like glucose get its building blocks

CO2 and energy from the sun

why is there a lot of energy in covalent bonds

2 atoms are sharing electrons so the electrons spend more time away from the nuclei

what happens to energy when bonds are broken

energy will be lost in the form of thermal energy, unless coupled with the creation of another bond

why do people with high metabolism get really high body temp

many bonds are being broken therefore lot of energy is being released

every catabolic reaction must be paired with an ____

anabolic reaction

what is chemical coupling

paring one reaction with a counter reaction

ex: hydrolisis and condensation

what is currency in biology / chemistry

ATP

what makes ATP cash

have 3 negatively charged oxygens and like charges repel meaning that bond has a lot of energy holding the molecule together, when that phosphate group is broken off a lot of energy is released making ATP very valuable for energy

what is ATP called when you break off that phosphate

ADP (adenosine diphosphate)

how does catabolism tie in with ATP

eat macromolecules → digest and absorb food pulling monomeric molecules into the cell → break their bonds and use the energy to synthesize ATP → now u have cash that can be used on anythign rather than just random monomers floating around

what do you spend ATP on

1. mechanical work (moving things like contraction of muscle)

2. active transport (process by which proteins can allow molecules that can’t normally cross cell membrane to cross)

3. chemical work / anabolism (chemical bondformation

ATP is constantly being cycled from ___

ATP to ADP to ATP to ADP

why is ATP constantly being cycled

it is NOT a stable molecule, therefore if not used it will break due to the negative charges that want to be pulled apart

due to ATP constantly being cycled, it cannot ___

be transferred from cell to cell, and will always be inside the cell constantly cycling

how do we make reactions happen

catalysts

what are catalysts

substance that speeds up chemical reaction or quickly causes change

made of organic molecules and protiens

what are proteins that drive chemical reactions / are catalysts for chemical reactions

enzymes

everything true about ____ is ____ about enzymes

proteins, true

when you want a particular reaction to happen, what can u do

synthesize the enzyme for that reaction

when you want to stop a reaction what can u do

hydrolize that enzyme

difference between chemical catalysts that are non organic vs in a living system

non organic catalyst: will drive reaction all the way untill all reactants have been used

in living system: u can control when to turn enzyme on and off

enzymes are very dependent on _____

optimal pH and optimal temperature

why are enzymes dependent on pH and temperature

cus they are proteins and proteins are extremely dependent on hydrogen bonds

ENZYMES ARE ____ _____

EXQUISITELY SPECIFIC: very specific for their one target

are catalysts altered by the reaction? what does this mean then?

not altered by reaction so they can constantly be reused over and over, since they are proteins when u don’t need them they can be recycled as amino acids

reactants that an enzyme is going to bind to are called ____

substrates

ending in -ase means…

enzyme

how does metabolism differ from chemistry done in a test tube

metabolism is chemistry we can do at

1. a reasonable temp (37 degrees celsius)

2. a reasonable concentration (2 substances can still find each other when mixed up with all the other substrates in a cell to make a reaction happen)

3. coupled to ATP (so energy isn’t lost as heat

4. we have control over when reactions stop and start

why are enzymes called matchmakers

they make it possible for 2 substrates to find each other even when mixed up with all the other substrates in a cell

metabolism is chemistry __ __ ___

done with enzymes

why is it important that we have control over our chemistry

so we can respond appropriately, rather than just letting things happen all the way until completion

as you make and break covalent bonds, the molecule goes through a ___ ___

transition state

what is a transitions tate

very awkward strained states that are at a higher energy state than either reactions or products in the reaction

can catabolic reactions occur spontaneously? why?

no because they NEED enzymes to get over a big hump

what would happen if catabolic reactions didn’t need enzymes

enzymes act as a gatekeeper for catabolic reactions, if they didn’t need them, then the catabolic reactions would be happening all the time causing your organic molecules to fall apart and needing a bunch of energy to constantly be building them up again

what do enzymes do to activation energy

they lower activation energy enough that the temperature will provide enugh heat to overcome the small amount of activation energy leftover

what would a graph look like of an anabolic reaction without an eznyme

the line would get super tall and it would be extremely difficult for 2 substrates to find each other, might have to wait a lifetime for them to meet

why would it be bad if we had to wait a lifetime for 2 substrates to meet

when u get chased by a bear, u need adrenaline to kick in now or u jus die

how does a living cell maintain metabolism without burning out

after a reaction there is just enough heat leftover from broken bonds to keep the molecules moving so that they can find the enzyme, the enzyme can provide the rest of the activation energy needed to get past transition state

why do we use metabolic pathways

for reactions that require more ATP than what a metabolic reaction can handle

what happens in metabolic pathways

the product of one reaction becomes the substrate of the next, so on and so on

why can’t you just jump from A straight to E in a metabolic pathway

would require WAY too much energy, could cause damage to the cell cus of how much heat would be released

why is it good that there are so many steps in metabolic pathways

more steps = more control over what u need and don’t need

what would happen to organic molecules if they weren’t in proper pH and temp

hydrogen bonds would break which would destabilize organic molecules like enzymes → stopping metabolic reactions from happening → no metabolic reactions means u dead

what are cofactors

metal ions that allow proteins to fold more properly

not all enzymes need but those that do won’t work unless cofactor is present

all coenzymes are ____

cofactors

describe coenzymes

molecules that must be present during the reaction but don’t necessarily bind to the enzyme'

mostly purpose is to carry electrons

example of co enzyme

if there were an enzyme that is going to cause an oxidation reaction, there must also be a reduction reaction, the co enzyme here would be the recipiet of those electrons and does the reduction half of that reaction

list the metabolic pathways of multienzyme systems

linear, cyclic

list the branched metabolic pathways and which one is which

divergent: 1 → 2

convergent: 2 → 1

where does information to make enzymes come from?

DNA

why would u want to control an enzyme / metabolic reaction

1. regulate metabolism, maintain homeostasis

2. kill microbes (sanitizing or sterilizing)

3. chemotherapy (encotherapy or infection)

what are the 2 types of inhibition and what do they do

1. competitive inhibition: inhibitor binds to active site so substrate doesnt

2. noncompetitive inhibition: inhibitors that bid to the outside of enzyme, bind to allosteric site which alters structure of active site preventing reaction from happening

what are the ways to control enzyme

control gene expression, or inhibit enzyme directly

Whats advantage of inhibiting enzyme over gene expression?

gene expression is actually easier u just shut down gene but that would shut down the whole reaction

inhibiting enzyme is good cus u can just stop one thing from happening, not have to shut off whole reaction