Exam 1: Metabolism and Cellular Respiration

metabolism

the sum of all the chemical reactions that are involved in catabolism and anabolism

anabolic reaction

building of smaller molecules into larger ones

requires the use/input of ATP

catabolic reaction

breaking down of larger molecules into smaller ones

releases ATP

enzyme

a protein that acts a catalyst

catalysts lower activation energy required for reactions, making them occur faster and more frequently

involved in both catabolic and anabolic reactions

coenzymes

non-proteins that assist enzyme function by bringing the resources to the enzyme so it can do its job

coenzymes needed for cellular respiration and why

NAD+/NADH and FAD/FADH2

they are electron carriers

redox reactions

a reaction that involves the transfer of electrons

OIL RIG

one substance is oxidized and one is reduced

oxidation

loses an electron

increases oxidation number - becomes more positive

reduction

gains an electron

decreases oxidation number - becomes less positive

metabolism of glucose to produce ATP

glucose is the basic unit of sugars that our body uses to produce ATP (energy)

how are sugar molecules stored

as large molecules called glycogen

what is glycogen broken down into and via what type of reaction

glucose, via a catabolic reaction

ATP

adenosine triphosphate

cellular energy

structure of ATP

adenine + ribose = adenosine

+ a 3-phosphate group

traits of the triphosphate group in ATP

all the phosphates are negative, so they want to repel each other, but are compressed when in ATP

ADP

adenosine diphosphate

one of the phosphate groups breaks off via ATP hydrolysis, releasing energy from the breakage of the bonds

ATP hydrolysis equation

ATP + H2O → ADP + P + energy

aerobic respiration

in the presence of oxygen

produces 40 ATP (net 36) per 1 glucose

waste products: water and carbon dioxide

anaerobic respiration

in the absence of oxygen

produces 4 ATP (net 2) per 1 glucose

waste product: lactic acid

aerobic and anaerobic respiration

both are ways to make energy (ATP) from glucose

waste products and amount of energy made differ

the 4 steps to cellular respiration

1. glycolysis

2. conversion to Acetyl-CoA

3. Krebs cycle

4. Electron transport chain

purposes of ATP

transport molecules, power muscle contractions, send electrical signals, etc

cellular respiration equation (aerobic)

1 glucose + 6O2 → 6CO2 + 6H2O + 36 net ATP (main products)

10 NADH, 2 FADH2 (other products, both net 0)

where does glycolysis occur

cytoplasm

what does glycolysis do

a. breaks down 1 glucose into 2 pyruvate molecules (2 ATP used to do this)

b. free phosphate added to each pyruvate; 2 NADH produced

c. 2 ATP produced from each pyruvate

d. 2 ATP used to transport the 2 pyruvates from the cytoplasm to the mitochondrial matrix

glycolysis products

main: 0 net ATP

other: 2 NADH

2 pyruvate

where does the conversion to Acetyl-CoA occur

mitochondrial matrix

what does the conversion to Acetyl-CoA do

a. convert the 2 pyruvate (3-carbon) molecules into Acetyl-CoA (2-carbon) by breaking off a CO2 and adding coenzyme A

b. NAD+ is simultaneously converted to NADH

conversion to Acetyl-CoA products

main: 2 CO2

other: 2 NADH

2 Acetyl-CoA

where does the Krebs cycle occur

mitochondrial matrix

what does the Krebs cycle do

convert the 2 Acetyl-CoA to NADH and FADH2

when the first 2 NADH are made, 2 CO2 are also made

1 ATP also produced

Krebs cycle products

main: 4CO2, 2 ATP

other: 6 NADH, 2 FADH2

where does the electron transport chain occur

mitochondrial inner membrane

what does the ETC do

use NADH and FADH2 to power electron transport chain and release H+ ions that will become H2O and be used by ATP synthase to make 34ATP

electron transport chain products

main products: 6 H2O, 34 ATP

other products: USES all the NADH and FADH2 that was made

what is required for the ETC

oxygen - making it definitively aerobic

what type of diffusion is occurring in the ETC

both active and facilitated passive

active by the ETC proteins that are pumping H+ ions against their gradient

then facilitated passive as the H+ ions flow back to area of low concentration through the ATP synthase

similarities between aerobic and anaerobic respiration

both undergo glycolysis

but then anaerobic is the processing of the pyruvates in the absence of oxygen

what does anaerobic respiration do

forms 2 lactic acid from the 2 pyruvate as a waste product

a rapid way to create 2 net ATP

returns NADH → NAD+ to be used again in glycolysis

when is anaerobic respiration optimal

when no oxygen is present

when cells run out of oxygen supplies

or in cells that do not have mitochondria

why is there a negative feedback loop for ATP production

it is a relatively unstable molecule - the phosphate groups repel each other and want to break off

ATP production negative feedback loop

if ATP is recognized to be too high, the steps of cellular respiration get stop signs so that no more ATP is produced

anabolic state

more calories are eaten than used up (surplus)

our bodies use the excess to build carbohydrate and lipid stores (glycogen and adipose tissue)

use amino acids to build proteins

catabolic state

less calories eaten than used up (deficit)

our bodies break down stored carbohydrates and lipids

proteins being broken down are a last resort in starvation states