Biological molecules: carbohydrates
20 review questions with answers for Biological molecules: carbohydrates. Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
Six-carbon monosaccharide that is the main fuel for respiration?
- GlucoseRight answer
- Fructose
- Ribose
- Galactose
What this set covers
Sugars of every size appear here, from glucose and ribose to maltose and sucrose, then the polysaccharides starch, glycogen and cellulose, with glycosidic bonds, branching, amylose and amylopectin, and the iodine and Benedict's tests.
- Common mix-up
- Students often mix up alpha and beta glucose, and so starch and cellulose: the only difference is the position of the OH group on carbon 1, which changes how the chains fold.
- Review tip
- Sketch amylose, amylopectin, glycogen and cellulose as simple chain diagrams, mark each bond type, and write one structure-to-function link under each.
All 20 questions and answers
Six-carbon monosaccharide that is the main fuel for respiration?
Answer: Glucose
Five-carbon sugar found in RNA nucleotides?
Answer: Ribose
Disaccharide made from two α-glucose molecules?
Answer: Maltose
Disaccharide made of glucose and fructose, used as table sugar?
Answer: Sucrose
Covalent link formed between two monosaccharides by condensation?
Answer: Glycosidic bond
α-glucose and β-glucose differ in the position of the –OH group on which carbon?
Answer: Carbon 1
Monomer of cellulose, with its C1 –OH pointing above the ring?
Answer: β-glucose
Class of carbohydrate that includes starch, glycogen and cellulose?
Answer: Polysaccharides
Polysaccharide that is the main carbohydrate store in animal liver and muscle?
Answer: Glycogen
Plant energy-storage polysaccharide made of amylose and amylopectin?
Answer: Starch
Unbranched component of starch that coils into a helix?
Answer: Amylose
Branched component of starch with both 1–4 and 1–6 glycosidic bonds?
Answer: Amylopectin
Glycosidic bonds that create the branch points in glycogen?
Answer: 1–6
Glycosidic bond joining the two glucose units in maltose?
Answer: 1–4
Feature of glycogen that gives many chain ends, so enzymes can release glucose rapidly?
Answer: Heavy branching
In cellulose, every other β-glucose unit is…?
Answer: Flipped upside down
Weak attractions that hold parallel cellulose chains together in microfibrils?
Answer: Hydrogen bonds
Strong cellulose microfibrils allow plant cell walls to resist…?
Answer: Turgor pressure
Colour of iodine solution in the presence of starch?
Answer: Blue-black
Reagent heated with a food sample to test for reducing sugars such as glucose?
Answer: Benedict's solution
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.