Respiration Key Terms and Processes

Question 1

What is Cellular Respiration?

Answer 1

A biochemical reaction in which cells convert sugar to CO2 and H2O

Question 2

Autotrophic Nutrition

Answer 2

The synthesis of organic materials from inorganic sources

Question 3

Heterotrophic Nutrition

Answer 3

The nutrition in which organisms ingest other organisms to obtain organic material

Question 4

Energy is used in…

Answer 4

• synthesis of complex structures
• active transport
• locomotion
• bio luminescence
• homeostasis
• production of electricity
• maintenance, repair and division
• activation of chemicals

Question 5

The Conservation of Energy

Answer 5

Energy cannot be created or destroyed, but can only be converted from one form to another.
Units are joules/kilo joules

Question 6

Metabolism

Answer 6

All reactions that take place within an organism

Question 7

Anabolism

Answer 7

Build up of larger, more complex molecules from smaller, more simple ones

Question 8

Catabolism

Answer 8

The breakdown of larger more complex molecules into smaller, more simpler ones

Question 9

ATP stands for…

Answer 9

AdenosineTriPhosphate

Question 10

What does ATP consist of?

Answer 10

ATP is a nucleotide that consists of three main structures: the nitrogenous base, adenine; the sugar, ribose; and a chain of three phosphate groups bound to ribose.

Question 11

How much energy is released when:

ATP + H2O?

Answer 11

30.6kJmol-1

Question 12

How much energy released when:

ADP + H2O?

Answer 12

30.6kJmol-1

Question 13

How much energy released when:

AMP + H2O?

Answer 13

14.2kJmol-1

Question 14

Why is ATP described as universal energy currency?

Answer 14

• it is hydrolysed energy, which means it is easily and immediately available to the cell in small manageable amounts
• it is continually hydrolysed and resynthesised
• it is found in all living organisms

Question 15

Describe the Mitochondria

Answer 15

• it is a double membraned organelle
• outer memrane is smooth
• inner membrane is folded into cristae
• matrix is a mixture of gel-like mixture of protein/lipid/DNA/ribosomes/coenzymes
• allows volatile reactions of aerobic respiration to be compartmentalised form the rest of the cell
• contains Kreb’s cycle’s enzymes
• found in all respiring organisms
• 1 micrometer in diameter
• 10 micrometers in length

Question 16

Describe the inner membrane

Answer 16

• different lipid composition to outer membrane
• impermeable to small ions
• folded
• has electron carriers and ATP synthase enzymes embedded

Question 17

Describe the matrix

Answer 17

• site of the link reaction
• NAD/FAD
• oxaloacetate
• mitochondrial DNA
• ribosomes
• co enzyme A

Question 18

Describe NAD

Answer 18

• nicotamine adenine dinucleotide
• reduced when two hydrogens with their electrons are accepted
• present in glycolysis, link reaction and Kreb’s cycle

Question 19

Describe FAD

Answer 19

• flavin adenine dinucleotide
• transfers one or two electrons or hydrogen atoms
• strong oxidising agent
  reduced in the Kreb’s cycle

Question 20

Describe Co enzyme A

Answer 20

• derived from vitamin B
• used in link reaction to transfer products of glycolysis into the mitochondria
• carries ethanoate groups made by oxidation during the link reaction and Kreb’s cycle

Question 21

Glycolysis occurs in the…

Answer 21

…cytoplasm of the cell

Question 22

For each glucose molecule entering the reaction…

Answer 22

• 2 molecules of ATP are used
• 4 molecules of ATP are produced
  (net gain : 2 ATPs)
• 2 molecules of reduced NAD are produced
• 2 pyruvates are produced

Question 23

What is substrate level phosphorylation?

Answer 23

Where ATP is formed directly using energy released from the oxidation of the substrate

Question 24

Describe Glycolysis

Answer 24

• phosphorylation of glucose
• so forming hexose (1,6) bisphosphate
• then splitting into 2 triose phosphates
• for the formation of pyruvate, the formation of reduced NAD
• pyruvate produced from triose phosphate
• total production 4 ATP, net production of 2 ATP

Question 25

Approximately how much chemical energy does glycolysis release?

Answer 25

Glycolysis releases less than 25% of the chemical energy stored in glucose

Question 26

Describe the Link Reaction

Answer 26

• pyruvate dehydrogenase removes hydrogen atoms from pyruvate
• these hydrogen atoms are accepted by NAD+ to produce reduced NAD
• pyruvate decarboxylase removes a carboxyl group, CO2 is formed
• CoA accepts acetate to form Acetyl CoA, which carries acetate into the Kreb’s cycle
• pyruvate is oxidised, NAD+ is reduced
• 2 x pyruvate, 2 x NAD+, 2 x CoA, 2 x CO2, 2 x reduced NAD, 2 x Acetyl CoA

Question 27

The link reaction occurs in…

Answer 27

…the mitochondrial matrix

Question 28

The Kreb’s cycle takes place in…

Answer 28

…the mitochondrial matrix

Question 29

Does the Kreb’s cycle require oxygen?

Answer 29

it doesn’t require oxygen, but it cannot take place without it, ∴ it is aerobic

Question 30

Respiratory substrates such as____ and ____ can enter aerobic respiration at the beginning of the Kreb’s cycle.

Answer 30

• fatty acids (broken down to acetates via CoA)

- amino acids (deaminated/changed to acetate/ pyruvate)

Question 31

The Kreb’s cycle is the oxidation of ____ to ____

Answer 31

Acetate to CO2

Question 32

Per acetate :

Answer 32

• 2 x CO2
• 1 x ATP
• 3 x reduced NAD
• 1 x reduced FAD

Question 33

What is the Kreb’s cycle?

Answer 33

It is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidization of acetate derived from carbohydrates, fats and proteins into carbon dioxide.

Question 34

The Krebs Cycle serves as what?

Answer 34

A central metabolic pathway for generating building blocks for the cell.

Question 35

Where does citric acid come from?

Answer 35

When Acetyl-CoA enters the Krebs cycle it combines with a four-carbon acid called oxaloacetic acid. The combination forms the six-carbon acid called citric acid.

Question 36

The metabolic pathway of the citric acid cycle chemically converts what to what?

Answer 36

Carbohydrates, fats, and proteins into carbon dioxide, and converts water into serviceable energy.

Question 37

In one concise sentence describe what happens in the Krebs cycle

Answer 37

• the citric acid cycle completed the oxidation of organic molecules generating many reduced NAD/FADH2 molecules
• acetyl group joins with oxaolacetate groups to form citrate which is then transformed (redox reaction) create electron carriers, and a byproduct of ATP

Question 38

How much ATP is produced per molecule of pyruvate?

Answer 38

One molecule of ATP

Question 39

How much ATP per molecule of glucose?

Answer 39

2 ATP s per glucose

Question 40

Products of the Kreb’s cycle? (two turns)

Answer 40

• 6 reduced NAD
• 2 reduced FAD
• 4 CO2
• 2 ATP

Question 41

What is the first stage of oxidative phosphorylation?

Answer 41

• reduced NAD and FAD are reoxidised when they donate the hydrogen, its then plait into protons and electrons
• electrons are accepted by the electron carriers
• protons go into solution in the matrix

Question 42

What is the second stage of oxidative phosphorylation?

Answer 42

• electrons are passed along a chaiun of carriers, energy is released and is used to pump protons into the intermembrane space
• an electrochemical gradient starts to build up
• protons diffuse through ion channels associated with ATP synthase

Question 43

What is stage three of oxidative phosphorylation?

Answer 43

• as protons flow through ATP synthase, the ezyme begins to rotate at the point
• ADP and an inorganic phosphate is joined together
• electrons and protons (hydrogen cations) combine with oxygen to form water