Cell Respiration - IB Biology HL

Cellular Respiration

a series of oxidative reactions by which cells gradually release (controlled release) energy from glucose and transfer it to molecules of ATP

Breaking Bonds

release of energy

"Goal" of controlled release of energy in cell

to trap energy in the form of ATP

aerobic cell respiration

cell respiration with oxygen sufficient

anaerobic cell respiration

cell respiration with unsufficient oxygen

anaerobic alcoholic fermentation

glucose undergoes glycolysis, pyruvates converted to ethanol and carbon dioxide by the use of two enzymes, with no further yield of ATP (though however allows the oxidation of NADH, letting more ATP be created by glycolysis), 2 ATP total per glucose, takes place in cytoplasm

anaerobic lactic acid fermentation

glucose undergoes glycolysis, pyruvates converted into lactic acid with no further yield of ATP by the use of one enzyme, total yield of 2 ATP per glucose, allows the oxidation of NADH, leeting more ATP and NADH to be created by glycolysis, takes place in cytoplasm, is reversible.

Overall process of aerobic cell respiration

glucose undergoes glycolysis, pyruvates converted into CO₂ and acetyl-CoA, acetyl-CoA undergoes Krebs cycle with large yield of ATP and CO₂, occurs in mitochondria, then the NADH and FADH enter the ETS, where a proton gradient is created by the power of e-, and chemiosmosis results through ATP Synthase, creating 34 more ATP.

Krebs cycle

part of aerobic cell respiration, enzymes decarboxylate carbon molecules into smaller ones with yield of 2ATP, 4CO₂, 6NADH, and 2FADH

General products formed from aerobic cell respiration

carbon dioxide, water and large yield of ATP

products formed from lactic acid fermentation

lactic acid, can be converted back to pyruvate

products formed from alcoholic fermentation

ethanol and carbon dioxide

glycolysis stage

stage common to all types of cell respiration, does not require oxygen.

Catabolism

Biological processes which primarily break down large storage and other chemicals, often releasing energy in the process.

Aerobic metabolism

Metabolism that can proceed only in the presence of oxygen.

Fermentation

A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.

Anaerobic Metabolism

The cellular process in which glucose is metabolized into energy without oxygen. Energy is produced in an inefficient manner with a higher concentration of waste products.

Oxygen

A gas that is brought into the body by the respiratory system that is vital to aerobic respiration

Carbon Dioxide

A gas that is expelled from the body by the respiratory system. It is the most oxidized form of glucose in aerobic respiration

Glucose

A monosaccharide molecule which acts as a chemical fuel for cell respiration.

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Oxidation

Loss of e-, gain of O, or the loss of H

Reduction

Gain of e-, loss of O, or the gain of H

NAD+/NADH

an organic molecule that serves as an electron carrier by being oxidized (losing electrons) to NAD+ and reduced (gaining electrons) to NADH

FAD/FADH2

FAD/FADH2 has electrons from glycolysis/krebs and acts as a shuttle. It donates the electrons in complex II of the electron transport chain, so not many electrons from this end up in the inner membrane space.

Exergonic reaction

A spontaneous chemical reaction in which there is a net release of free energy. Reactants have more energy than the products

Glycolysis

Catabolism of glucose (or other monosaccharides) to 2 pyruvate, 2 net ATP, 2NADH, 2ADP+P(i), and heat

Link Reaction

A part of the process of aerobic cellular respiration in which pyruvate is decarboxylated; oxidized by NAD+ to give acetate; combined with CoA --> acetyl CoA (no ATP produced).

Krebs/TCA/Citric Acid Cycle

A series of reactions that start with two molecules of acetyl-CoA derived from pyruvate - broken down into 4CO2 and form 2ATP along with 6NADH and 2FADH2, heat, and the recycling of 2 CoA and oxaloacetate. Occurs in mitochondria in aerobic conditions.

Electron Transport Chain

Any set of membrane-bound protein complexes and smaller soluble electron carriers involved in a coordinated series of redox reactions in which the potential energy of electrons transferred from oxidized donors is successively decreased and used to pump protons from one side of a membrane (matrix to inter-mem-space) to the other. Furthermore, chemiosmosis occurs in the ATP Synthase complex where 34ATP is created from 34ADP + P(i).

Pyruvate

A 3 carbon molecule that is formed by glycolysis and used for cellular respiration or fermentation

Lactate

A 3-Carbon compound produced from pyruvate during anaerobic metabolism by the use of one enzyme. This process is reversible. Its purpose is to allow the oxidation of NADH, and allow more ATP to be created through glycolysis

Oxidative Phosphorylation

The production of ATP using energy derived from the redox reactions of the electron transport chain; the third major stage of cellular respiration - occurs in ATP synthase from the appearance of catalytic sites from the spinning.

Substrate-Level Phosphorylation

a method of synthesizing ATP that occurs when an enzyme directly transfers a phosphate from an organic molecule (substrate) to ADP; happens in Glycolysis and Krebs cycle

Acetyl-CoA

2-carbon compound to which a molecule of CoA is attached; this is the derivative of pyruvate; it is required to be in this form to enter the Krebs Cycle

Cytochrome

any of several carrier molecules in the mitochondria of plant and animal cells, consisting of a protein and an iron-containing porphyrin ring and participating in the stepwise transfer of electrons in oxidation reactions: each cytochrome alternately accepts and releases an electron at a slightly lower energy level in the order

Intermembrane space

the fluid filled space between the inner and outer mitochondrial membranes

Chemiosmosis

An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Most ATP synthesis in cells occurs by chemiosmosis.

ATP Synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.

Mitochondrial Matrix

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle.