Lipids and Carbs structure/function

Carbon is one of the most abundant elements found in the molecules of living organisms. Which of the following statements does not refer to a property of carbon that allows it to play an integral biochemical role in the molecules of living things?

• A. It has four electrons in its outer shell meaning it can form four covalent bonds with other atoms

• B. When it bonds with hydrogen it creates a dipole that allows it to form hydrogen bonds with water and other polar molecules

• C. It can form double and triple bonds with adjacent carbon atoms to allow unsaturated compounds to form

• D. Produces a tetrahedral-shaped structure which allows the formation of varied carbon compounds which have different 3-D shapes

Which of the following bonds link two monosaccharides together to form a disaccharide?

• A. Hydrogen

• B. Ester

• C. Glycosidic

• D. Peptide

The diagram below shows a component of a triglyceride. Which of the following correctly identifies this component?

• A. Fatty acid

• B. Glycerol

• C. Amino acid

• D. Nucleotide

Which of the following features does not explain why lipids are excellent long-term storage compounds?

• They can be saturated or unsaturated

• Less body mass is required to store a given amount of energy

• They are insoluble and will not affect the osmolarity of the cell

• Lipids are energy dense molecules

Which of the following is not an example of a useful feature of molecular visualisation software?

• Molecules of cellulose, starch and glycogen can be rotated to view their 3D structure

• Visual comparisons can be made between the structure of cellulose, starch and glycogen

• The specific function of cellulose, starch and glycogen can be displayed

• The appearance of the atoms in the molecules can be changed

Which property of carbon makes it a good basis for organic molecules?

• It exists in hard and stable forms like graphite and diamond.

• It forms a varying number of covalent bonds to other atoms.

• It can form millions of different compounds in association with hydrogen and oxygen.

• It forms strong, ionic bonds with other atoms.

Which row of the table correctly identifies features of these molecules?

• Molecule 1 is a triglyceride; Molecule 2 is a phospholipid.

• Molecule 1 is a phospholipid; Molecule 2 is a triglyceride.

• Both molecules are triglycerides.

• Both molecules are phospholipids.

Which statement best explains why the molecular structure of starch is suited to its function?

• Many condensation reactions, in the breakdown of amylose and amylopectin, release stored energy.

• Many hydrolysis reactions, in the formation of amylose and amylopectin, allow the release of stored energy to fuel cellular processes.

• Amylose has a branched structure and amylopectin is coiled to give a compact structure for transport around the plant through the phloem.

• The amylose-amylopectin complex is insoluble, so it does not affect the osmolarity of the cell.

There is a naturally-occurring polysaccharide which has the structure of an unbranched chain of the molecule acetylglucosamine held together by β-1,4 glycosidic bonds. Which of the following polysaccharides has a structure similar to that described above?

• Glycogen

• Cellulose

• Amylopectin

• Amylose

Which of the following diagrams represents α-glucose?

• Diagram A

• Diagram B

• Diagram C

• Diagram D