Micro - Ch. 6 - metabolism: fueling cell growth

metabolism

all chemical reactions necessary to maintain life

catabolism

breakdown of molecules

“cats break stuff”

anabolism

building molecules 

coenzymes/cofactors 

compound that helps enzymes

• vitamins or minerals 

Enzyme classes

• oxidoreductases 

• transferases

• lyases

• hydrolases

• isomerases

• ligases

Oxidoreductases

causes losses or gains of oxygen and hydrogen

Transferases

transfers functional groups

lysases

removes atoms without use of water

Hydrolases

split bonds with water 

isomerases

rearrange molecules

ligases

joins molecules

What is the effect of temperature on enzymes?

high temperature speeds enzymes to a point of denaturation occurs and that then that causes a decrease in temperature which slows enzymes 

What is the effect of pH on enzymes?

high or low disrupts structure and function

inhibitors of enzymes

slows or stop enzyme activity

Types of inhibitors

1 competitive

2 noncompetitive 

Competitive inhibitors 

bind reversibly to enzymes active site 

Noncompetitive inhibitors

bind to a raondom spot on enzyme called “allosteric site” - can be reversible or not

What does ATP do?

stored energy

• a nucleic acid thats broken to release stored energy energy

What does ATP mean?

adenosine triphosphate 

What are the ways ATP is made

1 photosynthesis

2 aerobic respiration

3 anaerobic respiration (fermentation)

4 transferring a phosphate group to ATP

photosynthesis

uses sunlight and water

aerobic respiration

breakdown of glucose with oxygen

anaerobic respiration (fermentation)

breakdown of glucose WITHOUT or with LITTLE oxygen

transferring a phosphate group to ATP

phosphorylation (P)

ADP + P = ATP

parts of the chloroplast

thylakoid membrane (green pancakes)

stroma

What is the stroma in a chloroplast?

the fluid-filled space inside the chloropla that surrounds the thylakoid membranes

What happens in step 1 of photosynthesis?

light excites electrons locates in the thylakoid membrane and leaves chlorophyll and passes along electron transport chain

What happens in step 2 of photosynthesis?

high energy electrons move through the ETC releasing energy to pump hydrogen across thylakoid membrane

What happens in step 3 of photosynthesis?

water split to replace lost electrons, releasing oxygen (O2) into the air plus reducing hydrogen (H+)

What happens in step 4 of photosynthesis?

Hydrogen proton gradient of high concentration in thylakoid space drives ATP synthesis as H+ flow back into stroma through ATP synthesis (facilitated diffusion)

Recall: what is facilitated diffusion?

concentration of substance from high to low

What happens in step 5 of photosynthesis?

Electrons (e-) continue through the membrane to photosystem 1 where NADH+ accepts electrons and hydrogen to form NADPH

Step 5 for photosynthesis cheat

NADP+ + e- & H+ = NADPH

For steps 1-5 for photosynthesis they are:

light dependent

• ATP and NADPH were critical products

What happens in step 6 in photosynthesis?

CO2 enters the Calvin cycle from air and binds to sugars to for a 6 carbon atom

What happens in step 7 in photosynthesis?

the 6 carbon atoms split into two 3-carbon molecules (3PGA)

What happens in step 8 in photosynthesis?

ATP and NADPH converts the pair 3-carbon into G3P (high energy sugar)

From step 8 of photosythesis, what happens with the high energy sugar (G3P)?

Part of the G3P becomes glucose or carbohydrates

other half becomes RuBP to continue the cycle

What does step 8 of photosynthesis require more of?

requires more ATP

What is the oxidation of glucose equation (cellular respiration)?

C6H12O6 + 6O2 → 6CO2 + 6H2O + 38 ATP

What are the reactants of the oxidation of glucose equation?

C6H12O6 + 6O2

• glucose and oxygen

What are the products of oxidation of glucose equation?

6CO2 + 6H2O + 38 ATP

• carbon dioxide, water, ATP

How much ATP is produced from glucose being oxidized?

38 ATP

What does cellular respiration do?

“reverses” photosynthesis

How does cellular respiration reverse photosynthesis?

breaks down sugar using oxygen to make energy, water, and carbon dioxide

What are the basic steps of cellular respiration?

glycolysis → citric acid cycle/Krebs cycle → electron transport chain

Describe glycolysis

process of breaking down glucose

What happens in glycolysis?

glucose breaks into 2 pyruvate, 4 ATP (uses 2), 2 NADPH

What molecule begins the Krebs cycle?

the pyruvate acid we just made in glycolysis

How is acetyl CoA formed through the Krebs cycle?

pyruvic acid and coenzyme A joins

What forms citric acid?

oxaloacetic acid joins with acetyl CoA

What are the products of Kreb’s cycle?

CO2, NADH+, FADH2

What molecules are used with the electron transport chain?

NADH+ and FADH2

What happens in the ETC with NADH+ and FADH2?

they split to make H+ (protons) and electrons (e-)

What do the electrons pass through when released?

they pass through proteins that are the transport chains

What happens to the hydrogens (protons) in the ETC?

pumped into membrane to create a proton gradient

How is ATP made in the ETC?

uses the energy while the H’s & electrons join with oxygen to form water

fermentation

microorganism convert to pyruvate without oxygen to make acid, gases, and alcohol for bacteria and yeast

lipid breakdown

triglycerides are broken into glycerol and fatty acids

What do fatty acids go through?

beta oxidation

What does beta oxidation do to fatty acids?

breaks long fatty acid chain into smaller 2 carbon units (acetyl CoA)

Protein breakdown

broken into individual amino acids called “carbon skeletons” to join the Kreb’s cycle