Respiration

Cellular respiration

by Roy Mathews

​Glucose + oxygen --> carbon dioxide + water + ATP

​Cellular respiration is the process that releases energy in glucose to make ATP, the molecule that powers all the cell activities.

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​Cellular respiration involves many chemical reactions. These can be grouped into three stages:

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GLYCOLYSIS

​KREBS CYCLE (CITRIC ACID CYCLE)

​ELECTRON TRANSFER CHAIN

​GLYCOLYSIS

• ​Glycolysis occurs in the cytoplasm of the cell.

• ​Each glucose molecule is broken down into 2 pyruvate molecules.

• ​Two molecules of ATP are produced in the breakdown.

​Krebs cycle (Citric acid cycle)

• ​Occurs in the matrix of the mitochondria.

• ​As pyruvate passes around this cycle, the rearrangement of atoms occurs. CO2 and H atoms are produced.

• ​CO2 is a waster that diffuses out of the mitochondria.

• ​Hydrogen atoms are picked up by a carrier molecule (NAD)

​Electron transfer chain

• ​Occurs in the inner membrane of the mitochondria (cristae)

• ​Hydrogen atoms are ionised and their high-energy electrons are passed along a series of acceptor molecules.

• ​As the electrons are bounced along the electron transfer chain, their energy is used to form ATP from ADP.

Multiple Choice

Two substances needed for aerobic respiration are:

• Glucose and water

• Glucose and carbon dioxide

• Glucose and oxygen

• water and carbon dioxide

Multiple Choice

Structures that increase the surface of the inner membrane of the mitochondria are:

• cristae

• villi

• microvilli

• hair roots

Multiple Choice

Part of the cell where glycolysis, the first stage of cellular respiration occurs is:

• cytoplasm

• matrix of the mitochondria

• cristae of mitochondria

• endoplasmic reticulum

Multiple Choice

Place where Krebs cycle occurs in the cell is:

• cytoplasm

• matrix of the mitochondria

• cristae of mitochondria

• the outer membrane of mitochondria.

Multiple Choice

Cell organelle where most reactions of cellular respiration occurs is the:

• ribosome

• mitochondria

• lysosome

• Gogi apparatus

Multiple Choice

The electron transfer chain, the final stage of cellular respiration occurs in the:

• cristae of mitochondria

• matrix of mitochondria

• outer membrane of mitochondria

• the cytoplasm of the cell.

Multiple Choice

What stage of cellular respiration produces the most number of ATP?

• Glycolysis

• Krebs cycle

• Electron transfer chain

• anaerobic respiration

Multiple Choice

What statement is NOT correct about mitochondria?

• It has a double membrane

• The matrix contains several enzymes

• Substances cannot diffuse through its membranes.

• Cristae increase the surface area of inner membrane.

Multiple Choice

How many molecules of ATP are created from one molecule of glucose by aerobic respiration?

• 38

• 2

• 30

• 20

Multiple Choice

What substance is not needed for anaerobic respiration?

• Carbon dioxide

• oxygen

• glucose

• enzymes

Multiple Choice

What waste material is produced by both aerobic and anaerobic respiration?

• carbon dioxide

• lactic acid

• ethanol

• ATP

Multiple Choice

One of the reasons why large numbers of mitochondria are found in muscle cells is because:

• muscles get lots of oxygen

• muscle cells require lots of energy.

• muscle cells can tolerate high levels of CO2

• muscle cells are larger than other body cells.

Multiple Choice

Cells that carry out active transport contain large numbers of mitochondria because:

• Active transport requires ATP

• Active transport happens in the mitochondria

• the double membranes of mitochondria are not permeable

• active transport uses CO2 produced during respiration.