Review #3: Carbohydrates, Lipids, Cellular Respiration, and Photosynthesis Short Answer and Extended Response Released IB Questions
1.	(a)   Compare the use of carbohydrates and lipids in energy storage.
(4)
(b)	Compare how pyruvate is used in human cells when oxygen is available and when oxygen is not available.
(5)
(Total 9 marks)
2.	(a)	Glucose and galactose are examples of monosaccharides. State one other example of a monosaccharide.
 (1)
(b)	The equation below shows the production of glucose and galactose from lactose.

(i)	There are several different types of carbohydrate. State which type of carbohydrate lactose is.
 (1)
(ii)	State the type of chemical reaction that occurs when lactose is digested into glucose and galactose.
 (1)
(c)	Lactase is widely used in food processing. Explain three reasons for converting lactose to glucose and galactose during food processing.
 (3)
(d)	Simple laboratory experiments show that when the enzyme lactase is mixed with lactose, the initial rate of reaction is highest at 48°C. In food processing, lactase is used at a much lower temperature, often at 5°C. Suggest reasons for using lactase at relatively low temperatures.
 (2)
(Total 8 marks)
3.	(a)  Outline the role of hydrolysis in the relationships between monosaccharides, disaccharides and polysaccharides.
(4)
(b)	Describe the use of biotechnology in the production of lactose-free milk.
(6)
(c)	Explain the importance of enzymes to human digestion.
(8)
(Total 18 marks)

4.	Which chemical is shown in the diagram below?
		
A.	Saturated cis fatty acid
B.	Saturated trans fatty acid
C.	Unsaturated cis fatty acid
D.	Unsaturated trans fatty acid
(Total 1 mark)
5.	(a)	Body mass index (BMI) can be calculated from the mass (in kg) and height (in m) of an individual. The status of an individual can then be determined from a scale such as the one shown below.
BMI / kg m–2	Status	
< 18.5	Underweight	
18.5–24.9	Normal weight	
25.0–29.9	Overweight	
≥ 30.0	Obese	

(i)	Calculate the BMI for an individual whose mass is 74.0 kg and who has a height of 1.80 m.
 (1)
(ii)	On the basis of the BMI calculated in (a)(i), identify the status of this individual.
 (1)
(b)	Outline factors that can lead to an individual becoming obese.
 (3)
(Total 5 marks)
6.	Distinguish between the energy content per 100 g of fat, protein and carbohydrate.
 (1)
7.	(a)	State the energy content of 100 g of carbohydrate, fat and protein.
Carbohydrate: ..............................................................................................................
Fat: ...............................................................................................................................
Protein: .........................................................................................................................
(1)
(b)	Explain the possible health consequences of diets rich in fats.
 (3)
 (Total 4 marks)
8.	Explain possible health consequences of diets rich in fats.
 (3)
9.	Outline the implications for the health of a person who has a BMI of 16 kg m–2.
 (1)
10.	One recommendation for a healthy diet is to decrease the intake of saturated fatty acids. However, the relative benefit of replacing them with monounsaturated fatty acids, polyunsaturated fatty acids, or carbohydrates is still being debated. Diets with the same energy value, but rich in different fatty acids or carbohydrates, were fed to mice.
The table below shows the composition of plasma triglycerides, cholesterol, very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) in the diets.

Diet rich in:	Mean plasma concentration / mg dl–1	
	Triglycerides	Cholesterol	VLDL	LDL	HDL	
Saturated fatty acids	221	1014	373	608	90	
Monounsaturated fatty acids	346	1834	831	788	84	
Polyunsaturated fatty acids	101	801	242	526	89	
Carbohydrates	178	1518	672	744	93	
	[Merkel, M et al. 2001. Proceedings of the National Academy of Sciences. Vol 98. Pp 13 294–13 299. Copyright 2001, National Academy of Sciences, USA.]
(a)	State which diets increase the levels of cholesterol more than a diet rich in saturated fatty acids.
 (1)
(b)	Calculate the percentage increase in VLDL when changing from a diet rich in saturated fatty acids to a diet rich in carbohydrates.
 (1)
(c)	Compare a diet rich in saturated fatty acids and a diet rich in monounsaturated fatty acids.
 (2)
(d)	Evaluate the hypothesis that changing from a diet rich in saturated fatty acids to a diet rich in polyunsaturated fatty acids is healthy.
 (3)
(Total 7 marks)
11.	Outline the variation in the structure of fatty acids.
 (Total 3 marks)
12.	Outline two factors that affect the incidence of coronary heart disease.
(Total 4 marks)
13.	Compare the energy content of carbohydrate, protein and fat.
 (Total 2 marks)
14.	(a)	Draw a labelled diagram of a mitochondrion.
(3) 
(b)	Explain how the structure of a mitochondrion is adapted for its function.
 (2)
(Total 5 marks)

15.	This question refers to the following micrograph of a liver cell.
		
	In which organelle does the production of ATP, due to chemiosmosis, occur?
A.	A
B.	B
C.	C
D.	D
(Total 1 mark)
16.	Explain the link reaction that occurs between glycolysis and the Krebs cycle.
 (Total 4 marks)
17.	The electron micrograph below shows an organelle in a eukaryotic cell. What is the area labelled X and what is the type of reaction occurring there?

	X	Reaction	
A.	matrix	photolysis	
B.	stroma	Krebs cycle	
C.	stroma	photolysis	
D.	matrix	Krebs cycle	
(Total 1 mark)
18.	The diagram below shows a biochemical pathway in a yeast cell. Which of the following correctly identifies a compound in the diagram?
		
A.	I is fat.
B.	II is pyruvate.
C.	III is lactate.
D.	IV is carbon dioxide.
(Total 1 mark)
19.	The diagram below shows part of the respiratory pathway. The number of carbon atoms in each molecule is indicated.
		
(a)	(i)	Label pyruvate and acetyl coenzyme A on the diagram above.
(1)
(ii)	Indicate two places where decarboxylation occurs on the diagram.
(1)
(iii)	List one product other than carbon dioxide formed in this stage of respiration.
 (1)
(b)	State precisely where in a cell this stage of respiration is occurring.
 (1)
(Total 4 marks)

20.	(a)	Draw a labelled diagram showing the structure of a mitochondrion as seen in electron 
             micrographs.
(4)
(b)	Explain the relationship between the structure of the mitochondrion and its function.
 (3)
(Total 7 marks)
21.	What is chemiosmosis?
A.	Coupling of ATP synthesis to the electron transport and proton movement
B.	Phosphorylation of glucose in the mitochondrial matrix
C.	H+ ions moving down a concentration gradient into the mitochondrial matrix
D.	Activation of ATPase in order to synthesize ATP
(Total 1 mark)
22.	State a word equation for anaerobic cell respiration in humans.
 (1)
23.	Outline the process of glycolysis.
 (Total 5 marks)
24.	 Explain the process of aerobic cell respiration after glycolysis has occurred.
(Total 8 marks)
25.	Where is carbon dioxide produced in the mitochondrion?
		
(Total 1 mark)
26.	Outline anaerobic cell respiration in plant cells.
(Total 5 marks) 
27.	(a)	State the location of high proton concentration caused by electron transport in the mitochondrion.
 (1)
(b)	Outline the role of oxygen in cellular respiration.
 (2)
(c)	Explain how any two structural features of the mitochondrion are related to its function.
 (2)
(Total 5 marks)
28.	(a) Outline the role of chlorophyll and the effects of temperature, light intensity and carbon 
          dioxide concentration on the rate of photosynthesis.
(6)
(b)	Explain the production of energy during aerobic respiration from pyruvate that has been produced by glycolysis.
(8)
(Total 14 marks)
29.		Explain methods that can be used to measure the rate of photosynthesis.
(Total 5 marks)
30.	(a)   Outline condensation and hydrolysis reactions using a different example for each.
(5)
(b)	Explain methods by which the rate of photosynthesis can be measured, including conditions that affect the rate.
(9)
(Total 14 marks) 
31.	Explain how triose phosphate is produced and used in the chloroplasts of a plant.
 (Total 5 marks)
32.	Outline how light energy is used and how organic molecules are made in photosynthesis.
 (Total 6 marks)
33.	(a)	State the location in the chloroplast of the following reactions of photosynthesis.
Light-independent reactions: .......................................................................................
Light-dependent reactions: ..........................................................................................
(2)
(b)	Explain what happens to the electrons in the light-dependent reactions of photosynthesis.
 (3)
(Total 5 marks) 
34.	Draw a labelled diagram of the structure of a chloroplast as seen with an electron microscope.
 (Total 4 marks)
35.	(a)   Outline the light-dependent reactions of photosynthesis.
(6)
(b)	Explain the effect of light intensity and temperature on the rate of photosynthesis.
(8)
(Total 14 marks)
36.	(a)	Explain why carbon dioxide concentration is a limiting factor of photosynthesis.
 (3)
(b)	Explain the relationship between the structure of the chloroplast and its function.
 (3)
(c)	State two products of the light-dependent reactions.
 (2)
(Total 8 marks)