Carbohydrates
What are the two main ways cells use carbohydrates?
For energy-producing reactions and as structural materials
What does the term “monosaccharide” mean?
Simple sugar; a single sugar molecule
What are polysaccharides made of?
Connected monosaccharides (a polymer of glucose monomers)
What are the two main uses of lipids in the body?
Long-term energy storage and as building blocks
What are proteins made of?
Chains of amino acids (polypeptides)
What are the three groups of carbohydrates classified by the number of sugar molecules?
Monosaccharides, disaccharides, and polysaccharides
What is the general chemical formula for sugar molecules?
(CH₂O)ₙ where n = 3 to 8
Which polysaccharide is a polymer of alpha-glucose used by plants for energy storage?
Starch
Why are lipids hydrophobic?
Because they have nonpolar hydrocarbon tails
What type of bond connects amino acids?
Peptide bond
What is the most important monosaccharide used in cellular respiration?
Glucose
Give the formula for glucose.
C₆H₁₂O₆
Which polysaccharide is a polymer of branched alpha-glucose molecules used by animals for energy storage?
Glycogen
What are the three major groups of lipids?
Triglycerides, phospholipids, and steroids
Name the four levels of protein structure.
Primary, secondary, tertiary, and quaternary
What type of reaction forms disaccharides?
A dehydration reaction (water is lost)
What joins two monosaccharides to form a disaccharide?
A glycosidic linkage
Which polysaccharide is a polymer of beta-glucose and makes up plant cell walls?
Cellulose
What do triglycerides consist of?
One glycerol molecule and three fatty acids
What are the main functions or categories of proteins?
Structural, storage, transport, defensive, and enzymatic
What are the four examples of polysaccharides, and what do they do?
Starch (plant energy storage), glycogen (animal energy storage), cellulose (plant structure), chitin (exoskeleton structure)
Give three examples of disaccharides and their components.
Sucrose (glucose + fructose), lactose (glucose + galactose), maltose (glucose + glucose)
Why can humans digest starch but not cellulose?
Humans can break alpha-glycosidic bonds, but only specialized organisms can break beta-glycosidic bonds
What is the structural difference between saturated and unsaturated fatty acids?
Saturated have only single bonds (solid fats); unsaturated have one or more double bonds (liquid oils)
What are nucleic acids made of, and what do they store?
Polymers of nucleotides; store genetic information