Cell Respiration (DP IB Biology: HL)

Which row best describes an oxidation reaction?

	Hydrogen	Oxygen	Electrons	Energy
A	Loss	Gain	Loss	Released
B	Gain	Gain	Loss	Absorbed
C	Gain	Loss	Loss	Released
D	Loss	Gain	Loss	Absorbed

Which of the following best shows the reduction of NAD?

Which statements correctly describe phosphorylation and dephosphorylation reactions?

1. The phosphorylation of ADP is an endergonic reaction.
2. The dephosphorylation of ATP is an endergonic reaction.
3. The phosphorylation of ADP is a hydrolysis reaction.
4. The dephosphorylation of ATP is a hydrolysis reaction.

Which row shows the products of glycolysis?

	ATP	Pyruvate	Glucose	Reduced NAD
A	4	2	0	2
B	2	2	2	2
C	2	1	1	2
D	2	2	0	2

The diagram below shows a simplified Krebs cycle.

How many times does decarboxylation occur during the Krebs cycle?

 Which of the following is true of oxidative phosphorylation?

1. It is the last stage of aerobic respiration.
2. It takes place on the inner mitochondrial membrane.
3. It involves chemiosmosis.
4. It involves the electron transport chain.

The diagram below represents a simplified version of the electron transport chain and chemiosmosis.

 

Which row correctly describes the events labelled 1-4 above?

	1	2	3	4
A	Protons move across the cristae into the intermembrane space	Protons move across the cristae into the intermembrane space	Protons are pumped through ATP synthase	ADP is phosphorylated
B	Protons move across the cristae into the matrix	Protons move across the cristae into the matrix	Protons are pumped through ATP synthase	ATP is phosphorylated
C	Protons move across the cristae into the intermembrane space	Protons move across the cristae into the intermembrane space	Protons diffuse through ATP synthase	ADP is phosphorylated
D	Protons move across the cristae into the intermembrane space	Protons move across the cristae into the intermembrane space	Protons diffuse through ATP synthase	ATP is phosphorylated

Chemiosmotic theory was proposed by Nobel Prize winner Peter Mitchell in the 1960s, leading to what is considered to be a paradigm shift. 

Which of the following correctly defines the term paradigm shift?

The diagram below shows a mitochondrion.

Where in this organelle is ATP synthase found?

Which row correctly shows the features of a mitochondrion that can be observed and labelled on a drawing using a transmission electron microscope (TEM)?

	Mitochondrion shape	RNA and DNA	Cristae	Intermembrane space
A	Yes	Yes	Yes	Yes
B	Yes	No	Yes	No
C	Yes	Yes	No	Yes
D	Yes	No	Yes	Yes

In an investigation into the impact of enzyme inhibition on respiration, scientists used a molecule to inhibit transcription of the gene that codes for the enzyme LDHA.

Using the diagram, identify the likely effect this would have on the process of respiration.

1. Increased production of lactic acid
2. A build up of pyruvate in anaerobic conditions
3. Increased activity of the Krebs cycle in aerobic conditions

The diagram shows the electron transport chain in the membrane of the mitochondria.

Cyanide is a poison which causes cell death through inhibition of the final electron transport protein when it binds as shown in the diagram.

Which statements correctly describe the impact of cyanide binding to the final transport protein.

1. A decrease in pH of the intermembrane space
2. A decrease in production of H₂O
3. An increase in electrochemical gradient
4. Inhibition of ATP synthesis

From each molecule of substance X (in the diagram), how many molecules of ATP can be produced?

Which of the following statements about the Krebs cycle are correct?

1. NAD is oxidised and returned to the link reaction
2. Citrate is decarboxylated to form a 6 carbon molecule
3. FADH₂ is produced and sent to the electron transport chain
4. Oxidation of acetyl groups is coupled to reduction of hydrogen carriers.

The following steps describe processes involved in oxidative phosphorylation.

1. Redox reactions drive the movement of protons across the cristae to the intermembrane space
2. Oxygen molecules combine with protons and electrons to form water
3. NADH and FADH donate electrons to the first transport protein in the chain
4. Hydrogen ions (protons) are also released as the coenzymes are oxidised
5. A high concentration of protons in the intermembrane space creates an electrochemical gradient
6. Electrons move down the proteins in a series of redox reactions
7. Protons move down the electrochemical gradient through enzyme ATP synthase

Which of the following shows the correct sequence for these steps?