Metabolism: why do we need to eat and breathe?

Question 1

Metabolsm def

Answer 1

The totality of an organisms chemical reaction
Anabolism and catabolism

Question 2

Why do we eat

Answer 2

Our cells require constant supply of energy to support energy
All reactions our bodies undergo require energy
Energy is released
The complete breakdown of food: glycolysis and the citric acid cycle

Question 3

Most important fuels

Answer 3

sugars and fats→ Various types of carbs and lipids

Question 4

Autotrophs

Answer 4

Organisms that can create fuel molecules such as glucose fromH2o and CO2
Plants
Use sun energy

Question 4

catabolism

Answer 4

the breakdown of complex molecules into numerous simple ones

Question 5

Heterotrophs

Answer 5

Organisms that do not create fuel molecules but obtain energy from external chemical fuels → depend on autotrophs

Question 6

Why do we breath

Answer 6

Energy is trapped
ATP is produced: electron transport chain and oxidative phosphorylation

Question 7

Anabolism

Answer 7

the building of complex molecules from numerous simple ones
→ muscle or bone build up

Question 8

How does cell respiration work

Answer 8

The energy released is captured in the form of “high energy” chemical bonds in carriers such as ATP (pure energy carrier) and NADH/FADH2 (electron carriers)
E-s have energy, small amt compared to ATP but still have some
These carriers in turn serve as a portable sources of the energy and e-s needed for the synthesis of all molecules that forma a cell

Question 8

Cell respiration

Answer 8

the generation of (chemical) energy from food breakdown

Question 8

Energy carriers

Answer 8

ADP like empty battery
There is no energy
Can be charged w solar enegery for planst
Or pizza and food for humans
Cycle of charging and using the battery

Question 9

Aerobic respiration

Answer 9

sugar molecules (CH12O6) are broken down in many small steps (by enzymes) and oxidized with the help of oxygen (02).
Carbon dioxide (CO2) and water (H20) are released as final products.
Energy is trapped

Question 10

Electron carriers

Answer 10

The oxidation of sugar molecules leads to the extraction of electrons, which are transformd to electron carriers: NADH and FADH2
Electrons used to charge NAD and FAD
E- carriers can subsequently be used to transfer electrons to other molecules

Question 10

oxidation

Answer 10

Removal of e-s

Question 11

ATP type of energy

Answer 11

Can be immediately spent

Question 11

Reduction

Answer 11

Gain of e-s

Question 12

NADH and FADH

Answer 12

Needed to create new ATP molecules

Question 13

2nd category of glycolisis

Answer 13

Split molecule of fructose into 2 molecules of glycealdehyde 3 phosphate
Cleavage

Question 13

Breakdown of food

Answer 13

Breakdown of glucose to pyruvate (glycolysis; in cytosol or atrix of cell)
Breakdown of pyruvate to acetyl CoA (in mitochondria)
Complete breakdown (oxidation) of acutel CoA to CO2 and H2O in mitochondria
Oxidative phosphorylation and ATP synthesis ( in mitochondria

Question 14

Oxidative phosphorylation

Answer 14

where most energy is produced

Question 14

1st categories of glycolysis

Answer 14

Initial molecule turns into fructose 1,6 bipohospate
Energy needed to run this reaction
ATP sothat phosphate groups that are full of energy
Frctose tagged w two phosphate groups to kick it off and start reaction
Energy investment

Question 15

1st step of food breakdown Glycolysis

Answer 15

the pathway from glucose 6C to 2 pyruvate 3C
anaerobic pathway in which glucose is converted into pyruvate,
producing 2 molecules of ATP and 2 molecules of NADH

Question 16

3rd step of glycolisis

Answer 16

Energy generation of pyruvate
Energy also released here
Most important step

Question 16

Overall net gain of glycolosis

Answer 16

2 ATP ( 4 released, 2 used so only 2 gained)
2 NADH

Question 17

Fermentation

Answer 17

pyruvate can be fermented to either lactate or ethanol or enter an oxidative pathway (the citric acid cycle [CAC] and oxidative phosphorylation)
Some prokaryoes are anaerobic
Live w out oxygen
Some cells in our body aswell
In order to get energy they use anaerobic breathing or fermentation
For anaerobic organisms glycolisis is the main source of ATP
Pyruvate is then converted by fermentation into simpler compounds like ethanol
Why? Regeneration of NAD+

Question 18

What is the CAC

Answer 18

Acetyl CoA (2C*) enters the 8-steps citric acid cycle

Question 18

Ocidation of pyruvate to acetyl CoA

Answer 18

Pyruvate is transported into mitochondria and then oxidized, producing CO2, NADH and Acetyl CoA
Transport protein used to transport pyruvate thru mitochondrial wall
Acytyl CoA has a lot of energy

Question 18

2nd step of food breakdown

Answer 18

Oxidation of pyruvate to acetyl CoA

Question 19

3rd step of food breakdown

Answer 19

The citric acid cycle

Question 20

Where does CAC take place

Answer 20

Mitochondrial matrix

Question 21

Why does the CAC take place

Answer 21

Accounts for about two-thirds of the total oxidation of
carbon compounds

Question 22

The CAC net result

Answer 22

Release 3 NADH
1 GDP
1FADH2
Loose two e- carrier and one energy carrier

Question 23

First step of CAC

Answer 23

acetyl coa joins with a four-carbon molecule, oxaloacetate, releasing the
CoA group and forming a six-carbon molecule called citrate.

Question 24

The cycle is step into 2 parts

Answer 24

Decarboxylation
Regeneration of oxyl acetate

Question 24

the CAC and oxidative phosphorylation

Answer 24

the CAC is the central metabolic hub in the mitochondria of all aerobic cells; it produces ATP and electron carriers (NADH and FADH2), which deliver their electrons to the electron transport chain (ETC)

Question 25

8th step in CAC

Answer 25

In the last step of the citric acid cycle, oxaloacetate—the starting four-carbon compound—is regenerated by oxidation of malate. Another molecule of NAD+ is reduced to NADH in the process

Question 25

2nd CAC step

Answer 25

citrate is converted into its isomer, isocitrate.
This is actually a two-step process, involving first the removal and then the addition of a water molecule

Question 26

What happens during decarboxylation

Answer 26

2 Carbon molecules are lost
Important bc glucose is made of 6C
This is divided into two pyruvates of 3C
1C lost in production of pyruvate to acetyl CoA
Acetyl CoA has 2C
Loose 2C in CO2
Now all Carbons of the glucose originally are lost
All pyruvate is broken down
All energy is dropped into ATP,GTP, NADH, and FADH+

Question 27

Oxidative phosphorylation

Answer 27

Electron transport and chemostasis

Question 28

Chemioosmosis

Answer 28

Backflow of protons (H+) down their electrochemical gradient through a protein complex (ATP synthase) → Synthesis of ATP

Question 28

Electron transfer cain (ETC)

Answer 28

ENERGY OF E- CHAIN IS USED TO PUMP H+ ACROSS THE INNER MEMBRANE

Question 29

Electron transport

Answer 29

Transter of high-energy electrons (sourced by NADH and FADH,) along an electron-transport chain until a final acceptor (O2) → Creation of a H+ gradient over the inner mitochondrial membrane (thus between matrix and intermembrane space)
Proteins can move e-s along the membrain
NADH to FADH2 from citric acid cycle
electrons are transferred to the final electron acceptor O2, producing H2O
* Electron transfer in the ETC is accompanied by the generation of a proton gradient, which fuels ATP synthesis

Question 30

The complete (aerobic) oxidation of 1 molecule of glucose yields

Answer 30

30-32 ATP