Biology 1113: Lecture 3 (carbohydrate) Flashcards
What are the primary components of carbohydrates?
Carbon (C), Hydrogen (H), and Oxygen (O), often in the ratio 1:2:1.
What is the general formula for carbohydrates?
(CH₂O)n.
Why are carbohydrates hydrophilic?
Due to their polar C=O and -OH functional groups.
What are the main functions of carbohydrates?
Energy storage, structural support, and serving as raw materials for other molecules.
What is a monosaccharide?
A simple sugar with one ring structure.
Name three common monosaccharides.
Glucose, fructose, and galactose.
Why are monosaccharides important?
They are the monomers of carbohydrates, essential for digestion, absorption, and cellular respiration.
How do monosaccharides differ?
By the number of carbons, position of the C=O group, and orientation of the -OH groups.
What are the two forms of glucose in ring structures?
Alpha (α) and beta (β) glucose, differing in the position of the -OH group.
What is a disaccharide?
Two monosaccharides covalently bonded together.
Give examples of disaccharides and their components.
Sucrose: Glucose + Fructose
Lactose: Glucose + Galactose
What causes lactose intolerance?
Inability to break the bond between glucose and galactose due to an enzyme deficiency.
What reaction forms disaccharides?
A condensation reaction forming a glycosidic linkage.
What is a polysaccharide?
Many monosaccharides linked together.
Name two energy-storing polysaccharides and where they are found.
Starch: Plants
Glycogen: Animals
Why does glycogen lead to ‘water weight’?
It is stored with a lot of water.
What structural polysaccharide is found in plants?
Cellulose.
Why can’t humans digest cellulose?
It consists of β-glucose, which humans lack the enzyme to break down.
What are the structural polysaccharides in fungi and bacteria?
Chitin: Fungi and insects
Peptidoglycan: Bacterial cell walls
What makes cellulose strong?
Linear parallel strands linked by hydrogen bonds.
What are ‘simple sugars’ on nutrition labels?
Monosaccharides and disaccharides.
How do complex carbohydrates affect blood sugar differently from simple sugars?
They take longer to digest, leading to a slower and more sustained energy release.
What roles do carbohydrates play in cell identity?
They act as markers on glycoproteins and glycolipids, aiding in cell-cell recognition and signaling.
What determines blood type in humans?
The specific oligosaccharides attached to membrane proteins or lipids.
