Biology 9700 · AS & A Level

Carbohydrates and lipids

100 practice questions on Carbohydrates and lipids, with worked solutions and instant marking.

The table presents some details about four carbohydrate polymers. Which two polymers make up starch?

Feb/March 2016

Which molecule in the key represents sucrose?

Feb/March 2016

Which of these statements about triglycerides and phospholipids are correct?

Feb/March 2016

The table presents some information about carbohydrate polymers. Which row refers to amylose?

Feb/March 2017

Which table row concerning $\alpha$-glucose and $\beta$-glucose molecules is correct?

Feb/March 2017

Sugars can be represented in ring form as well as in a linear form. Which sugar molecules could this diagram’s linear structure represent?

Feb/March 2018

Which concentrations could be obtained by carrying out a serial dilution of an $8.00\%$ glucose solution?

Feb/March 2018

A student recorded the following claims about polysaccharides. 1. Amylose is produced by condensation reactions involving $\beta$-glucose monomers. 2. Branches in amylopectin molecules are formed between carbon atoms $1$ and $4$ on $\alpha$-glucose molecules. 3. In unbranched $\beta$-glucose chains, each monomer is rotated $180^{\circ}$ relative to the monomer next to it. Which statements are correct?

Feb/March 2018

A student made four claims about what occurs during the hydrolysis of a carbohydrate. Which claims are correct?

Feb/March 2019

The table compares three molecules, X, Y and Z, each of which contains only carbon, hydrogen and oxygen. The percentage of carbon, hydrogen and oxygen atoms in every molecule is given. Which row gives the correct identification of molecules X, Y and Z?

Feb/March 2019

Which statements describing the differences between phospholipids and triglycerides are correct?

Feb/March 2019

The diagram depicts a molecule made up of three hexose sugars labelled 1, 2 and 3. Which row correctly identifies examples of carbohydrates in which these three hexose sugars are found?

Feb/March 2019

What feature of glycogen sets glycogen apart from starch?

Feb/March 2019

A triglyceride contains ......1...... bonds that are formed by joining fatty acids to ......2...... . Which row completes this statement correctly?

Feb/March 2021

Which diagram shows a molecule of $\alpha$-glucose?

Feb/March 2021

Which of the following statements about glycosidic bonds are correct?

Feb/March 2021

Which row presents the characteristics of a carbohydrate polymer located within animal cells?

Feb/March 2022

The statements outline the structure of a polysaccharide present in the cell walls of some plants. Which of the statements are also true of cellulose?

Feb/March 2022

The formula for a saturated fatty acid is $\text{C}_n\text{H}_{2n}\text{O}_2$. Which of these fatty acids would be unsaturated?

Feb/March 2022

What feature allows triglycerides to carry out their roles in living organisms?

Feb/March 2022

Sugars that have a ring form can also exist in a linear form. Which sugar molecules might be shown by the linear structure in the diagram?

Feb/March 2022

Which row correctly pairs each molecule with a bond type that is present?

Feb/March 2022

Which molecules include at least three double bonds?

Feb/March 2023

Which statements are true for amylose and for amylopectin as well?

Feb/March 2023

Which statement gives a correct comparison between saturated triglyceride molecules and unsaturated triglyceride molecules with approximately the same molecular masses?

Feb/March 2023

Which of the following statements about triglycerides is correct?

Feb/March 2024

The diagram illustrates the structure of a section of a peptidoglycan molecule. What type of $1,4$ linkage is present, and how many peptide bonds can be seen in this section of the molecule?

Feb/March 2024

Antibiotic-resistant strains of $\textit{Mycobacterium tuberculosis}$ are a serious issue in the treatment of TB. A new antibiotic, teixobactin, may be highly effective at destroying $M.\ \textit{tuberculosis}$, with only a small chance that the bacteria will develop resistance to teixobactin. Penicillin and related antibiotics attach to one protein, whereas teixobactin attaches to two lipids that are necessary for the bacterial cell wall to form. Teixobactin binds to parts of the two lipids that remain unchanged across many different species of bacteria. Which statements help to explain why the use of teixobactin is considered less likely to cause the evolution of antibiotic resistance than the use of many other antibiotics, such as penicillin?

Feb/March 2024

Which diagrams illustrate the release of a water molecule as a glycosidic bond forms?

Feb/March 2024

Which molecules include $\text{C}=\text{O}$ bonds in their structural formulae?

Feb/March 2024

Plant cell walls gain strength from cellulose molecules that are organised into several layers. In each layer, the cellulose molecules all lie in the same direction (parallel). Which row shows the bonds that join neighbouring cellulose molecules within each layer and the arrangement of cellulose molecules in different layers?

Feb/March 2025

Galactogen is a storage polysaccharide found in certain animal species. It is a branched polymer made from β-galactose monomers. Which comparison between galactogen and another polysaccharide accurately states one similarity and one difference?

Feb/March 2025

What may happen in a hydrolysis reaction?

Feb/March 2025

Sugars that are in a ring form can also exist in a linear form. Which sugar molecules might be shown by the linear structure in the diagram?

Feb/March 2025

Which statement concerning triglycerides is correct?

Feb/March 2025

How many fatty acid residues are typically found in one phospholipid molecule?

May/June 2010

What characteristic sets starch apart from glycogen?

May/June 2010

Which statement explains how the molecular structure of starch is adapted to its function?

May/June 2010

Which diagram shows part of the ring structure of a molecule of $\beta$-glucose?

May/June 2010

Which statement explains how the molecular structure of starch is adapted to its function?

May/June 2010

A phospholipid molecule normally contains how many fatty acid residues?

May/June 2010

The diagram illustrates a tropical ocean food chain with $10\%$ efficiency of energy transfer between trophic levels. Net primary production of phytoplankton is $1300\,\text{g m}^{-3}\,\text{yr}^{-1}$. What is the annual net primary production for the carnivorous zooplankton and the tuna?

May/June 2010

What feature sets starch apart from glycogen?

May/June 2010

Which diagram shows part of the ring structure of a $\beta$-glucose molecule?

May/June 2010

Which option correctly pairs the functional and structural characteristics of cellulose, collagen, glycogen or triglyceride?

May/June 2011

What type of sugar and what kinds of bonds are present in a DNA molecule?

May/June 2011

Each year, around 1 047 000 kJ of solar light energy falls on 1 square metre of grassland. The table indicates how this energy is transferred. How much energy is taken up by the grass for photosynthesis?

May/June 2011

During hydrolysis, which molecular bonds are broken when a molecule of glycogen is converted into glucose?

May/June 2011

Certain foods include ‘hydrogenated vegetable oils’. These are unsaturated fats that have been changed into saturated fats. Which property of the fats would be different?

May/June 2011

Which row gives the description of a triglyceride?

May/June 2011

Which polysaccharides are branched, and which are unbranched?

May/June 2011

Three carbohydrate molecules are illustrated. Which two molecules join together to make one molecule of sucrose?

May/June 2011

Each year, one square metre of grassland gets about $1\,047\,000\ \text{kJ}$ of solar light energy. The table indicates how this energy is transferred. How much energy is taken in by the grass for photosynthesis?

May/June 2011

What type of sugar and what kinds of bonds are present in a DNA molecule?

May/June 2011

Certain foods include ‘hydrogenated vegetable oils’. These are unsaturated fats that have been changed into saturated fats. Which characteristic of the fats will have altered?

May/June 2011

Which molecular bonds are broken during hydrolysis when a glycogen molecule is converted into glucose?

May/June 2011

Which option correctly links the functional and structural characteristics of cellulose, collagen, glycogen or triglyceride?

May/June 2011

The photomicrographs display cross-sections of arteries taken from a non-smoker and a smoker. Using the evidence shown above, which disease is most likely to develop in the smoker?

May/June 2012

Which statement concerning polysaccharides can describe both amylopectin and cellulose? 1 neighbouring glucose molecules are rotated through $180^\circ$ 2 features $1,4$ glycosidic bonds 3 polymer formed from $\alpha$-glucose

May/June 2012

In the key, which molecule is sucrose?

May/June 2012

Which molecules below have structural formulae that include C=O bonds? 1 fatty acids 2 glucose 3 glycerol

May/June 2012

The diagram depicts two molecules of glucose. Four possible bonding sites are marked p, q, r, and s, and t, u, v, w. During condensation of these two molecules as a glycogen molecule is formed, at which positions could bonds be made?

May/June 2012

Glycogen is a polymer made from glucose. Which description best outlines its structure?

May/June 2012

Which molecules have $\text{C}=\text{O}$ bonds?

May/June 2012

Which statement about polysaccharides can be applied to both amylose and amylopectin?

May/June 2012

Which molecule in the key represents sucrose?

May/June 2012

Which statement about polysaccharides could be applied to both amylopectin and cellulose?

May/June 2012

Which molecules have structural formulas that include C=O bonds?

May/June 2012

One naturally occurring polysaccharide is made up of a straight, unbranched chain of acetylglucosamine molecules joined by $\beta$-$1,4$ glycosidic bonds. The $-$CH$_2$OH groups alternate from one side of the polysaccharide chain to the other. Many hydrogen bonds are formed between these straight chains. Which polysaccharide has a structure similar to the one described?

May/June 2013

In what way does smoking raise the likelihood of developing atherosclerosis?

May/June 2013

X and Y represent the structures of two hexose sugars. Which statement is correct?

May/June 2013

The structural formula for a carbohydrate molecule may be represented as: (a Fischer projection with an aldehyde group $\text{C}=\text{O}$ at the top, a carbon chain with alternating $\text{H}$ and $\text{OH}$ side groups, and a terminal $\text{CH}_2\text{OH}$ group.) Which of the molecules could be shown by this formula?

May/June 2013

What happens when sucrose is hydrolysed into monosaccharides?

May/June 2013

The diagram shows part of a glycogen molecule. In what way is this molecule different from an amylose molecule?

May/June 2013

A carbohydrate molecule can be represented by a structural formula. Which one of the following molecules could this formula represent?

May/June 2013

A polysaccharide that occurs naturally is a branched chain made of $\alpha$-glucose. Its unbranched sections are joined by $\alpha$-1,6 glycosidic bonds, and it has a small number of branches that are connected by either an $\alpha$-1,3 glycosidic bond or an $\alpha$-1,4 glycosidic bond. Which polysaccharide has a structure most like the one described?

May/June 2013

A carbohydrate molecule’s structural formula can be displayed. Which of these molecules could be represented by this formula?

May/June 2013

The diagram displays a section of a carbohydrate molecule made from glucose. What is the name of this molecule?

May/June 2013

The enzyme catechol oxidase makes a brown colour appear when slices of many fruits, such as apples, are left exposed to air. It catalyses this reaction: $\text{catechol} + \text{oxygen} \xrightarrow{\text{catechol oxidase}} \text{quinone} + \text{water}$. The quinone is then rapidly oxidized further in air to form a brown-coloured substance. Catechol and quinone are colourless. A student studied how fast this reaction occurs under different conditions.

May/June 2013

Which molecules represent the structures of $\alpha$-glucose and $\beta$-glucose?

May/June 2014

In unsaturated lipid molecules, where are the double bonds found?

May/June 2014

Which molecule has a glycosidic bond?

May/June 2014

Which statement explains how substances in cigarette smoke raise the chance of atherosclerosis developing?

May/June 2014

Which option identifies the basic unit of glycogen?

May/June 2014

What features make a cellulose molecule suitable for its function?

May/June 2014

In triglyceride molecules, at which positions are double bonds found?

May/June 2014

During the hydrolysis of an amylose molecule, which bonds are broken? 1 $\alpha(1,4)$ 2 $\beta(1,4)$ 3 $\alpha(1,6)$ 4 $\beta(1,6)$

May/June 2014

Which statement explains how starch’s molecular structure is adapted to its function?

May/June 2014

Which statements comparing biological molecules are correct? 1 A collagen molecule is a fibrous protein made up of many amino acids with hydrophobic R-groups, whereas a haemoglobin molecule is a globular protein with no amino acids with hydrophobic R-groups. 2 Breaking down sucrose by hydrolysis causes glycosidic bond breakage and yields equal amounts of fructose and $\alpha$-glucose molecules, whereas hydrolysis of cellulose gives only $\beta$-glucose molecules. 3 The glycosidic bonds in glycogen are formed between two $\alpha$-glucose molecules, whereas in amylopectin the bonds are formed between an $\alpha$-glucose molecule and a $\beta$-glucose molecule.

May/June 2014

Which statement correctly describes the structure of amylose and cellulose?

May/June 2015

Which row correctly pairs the descriptions of biological molecules with where they are found? 1 a linear polymer made from 1,4 linked $\beta$-glucose molecules 2 a bipolar, phosphate containing molecule 3 a highly branched polymer made from 1,4 and 1,6 linked $\alpha$-glucose molecules

May/June 2015

Which bonds are responsible for holding the structure of cellulose together?

May/June 2015

What type of bonds are present in glycogen?

May/June 2015

Which one of the molecules is $\alpha$-glucose?

May/June 2015

$X$ and $Y$ are two monomers present in biological polymers. In which of cellulose, glycogen, amylopectin and amylose is each monomer found?

May/June 2016

Chitin is a polysaccharide made up of long, unbranched chains of the monosaccharide acetylglucosamine, joined by $1,4$ glycosidic bonds. Acetylglucosamine has a structure similar to glucose, but it also contains nitrogen, which enables hydrogen bonds to form between neighbouring chains of chitin when they are aligned parallel to one another. Which polysaccharide has the closest structural similarity to chitin?

May/June 2016

Which of the following statements about triglycerides is correct?

May/June 2016

Which of these statements about fatty acids are correct?

May/June 2016

The diagrams depict four monosaccharides that have the formula $\text{C}_6\text{H}_{12}\text{O}_6$. Which diagram shows $\beta$-glucose?

May/June 2016

The diagram illustrates how different polysaccharides are related and the glycosidic bonds joining their monomers. Which row is correct?

May/June 2016