Respiration

Question 1

What elements are recycled through photosynthesis and cellular respiration

Answer 1

1. Carbon
2. Hydrogen
3. Oxygen

Question 2

3 different kinds of work

Answer 2

-Chemical work (Molecule formed)
-Mechanical work (Protein filament moved)
-Transport work (Solute transported)

Question 3

Respiration vs breathing

Answer 3

-Closely related
-Breathing (Process of bringing air into lungs and out of lungs)
-Respiration (Carries out in muscle cell)
EX: O2-> H2O + CO2 + ATP

Question 4

Food as a requirement for biological rxns

Answer 4

-As much as 75% of the food we eat each day goes to keeping us alive through our biological RXNS

Question 5

How does a cell extract energy from glucose

Answer 5

-By transferring electrons during chemical RXNS
-Loss of hydrogen atoms (becomes oxidized)
-Gain of hydrogen atoms (becomes reduced)

Question 6

Aerobic metabolism

Answer 6

-Food is eventually completely oxidized by CO2 + H20 by molecular oxygen
-Food molecules are incompletely oxidized to lactic acid/lactate
-As a result: Energy yield per unit molecule of glucose in anerobic respiration is only a fraction of the energy yield in aerobic respiration

Question 7

Anaerobic metabolism

Answer 7

its the opposite :) (and less effective)

Question 8

Glycolysis

Answer 8

-The anaerobic precursor to aerobic respiration
-1 molecule of glucose, with 6 carbon atoms, goes through a series of RXNS to produce 2 molecules of pyruvate
-9 enzyme -catalyzed RXNS… a unique enzyme of each RXN

STEPS
-Steps 1-3: Glucose is energized using ATP
-Step 4: 6 Carbon intermediate split into two 3 carbon pyruvates
-Step 5: A redox RXN generates NADH
-Steps 6-9: ATP + Pyruvate produces

Question 9

Link between citric acid cycle/kreb’s cycle and glycolysis

Answer 9

Prior to citric acid cycle

pyruvate moves from cytoplasm to mitochondria

Pyruvate is oxidized, becomes acetyl CoA

Pyruvate does not enter aerobic respiration directly

Question 10

Citric acid/ kreb’s cycle steps

Answer 10

1. Carboxyle group is removed, releasing CO2 - this step proceeds twice for every molecule of glucose metabolized
2. 2C group is oxidized and electrons are picked up by NAD+ forming NADH - will be used later to generate ATP for energy
3. Enzyme bound acetyl group is transformed to CoA, peoducing a molecule of acetyl CoA - Then converted to be used in next pathway of metabolism - citric acid cycle

Question 11

Oxidative phosphorylation

Answer 11

1. Electron trasport system
2. electron transport chain
3. Chemiosmosis

Question 12

Electron transport chain

Answer 12

Electrons fall from glucose to oxygen through a series of electron carriers, releasing energy

The released energy is used to synthesize ATP
Released in steps

Question 13

Chemiosmosis

Answer 13

Electrons harvested from glucose drive protons across membranes against their concentration gradient (Active transport)

The return of the protons by diffusion generates ATP

Question 14

Raw materials for biosynthesis

Answer 14

Not all food molecules are destined to be oxidized as fuel for making ATP

Food molecules also provide the raw materials for biosynthesis - the production of organic molecules

The cell must be able to make its own molecules to build its structures and perform its functions,

Question 15

Biosynthetic pathways

Answer 15

Humans eat mostly carbohydrates, proteins and fats - not only glucose

Some food is oxidized for making ATP
some is used for biosynthesis

Proteins are burned for fuel last - amino acids converted to intermediates in glycolysis or citric acid cycle

Question 16

Fats

Answer 16

Most efficient molecules for long term energy storage

with their many hydrogens atoms, fats provide many energy rich electrons

A gram of fat yeilds over two times as much ATP as does a gram of carbohydrates

Question 17

Starches

Answer 17

Bread, potatos and pasta

Long chain of glucose molecules

so eating excess starch can do the same thing as eating excess sugar

Question 18

Why storing fat rather than sugar has it’s advantages

Answer 18

Energy from fat

Question 19

Cyanide

Answer 19

Derived from the seeds of the prunus family, which includes cherries, apricots and almonds

Rapid acting potentially deadly chemical that can exist in various forms:
1. Colourless gas - hydrogen cyanide (HCN)
2. or crystal form - sodium cyanide
Mitochondrial toxin

Question 20

CO

Answer 20

Carbon monoxide does the same thing as cyanide

why carbon monoxide is lethal

Question 21

Exercise

Answer 21

Dramatic test of the bodies homeostatic control systems

increase in muscle oxygen required
large amount of carbon dioxide produced

must be countered by increases in both breathing and blood flow

Question 22

Mitochondria and energy

Answer 22

Number of mitochondria increases in the muscles of people who train

Therefore there is a greater reliance onn the citric acid cycle and the electron transport system to generate energy