Which polysaccharide stores energy in animal cells?
A) Starch
B) Cellulose
C) Glycogen
D) Chitin
C) Glycogen
All lipids share which property?
A) Polar
B) Hydrophilic
C) Hydrophobic
D) Charged
C) Hydrophobic
What is the monomer of proteins?
A) Monosaccharide
B) Amino acid
C) Fatty acid
D) Nucleotide
B) Amino acid
The three components of a nucleotide are:
A) Sugar, phosphate, base
B) Amino acid, phosphate, base
C) Fatty acid, sugar, base
D) Ribose, glycerol, lipid
A) Sugar, phosphate, base
Which structure is found in all cells?
A) Nucleus
B) Plasma membrane
C) Mitochondria
D) ER
B) Plasma membrane
What is the simplest type of carbohydrate that cannot be broken down into smaller sugar units?
A) Disaccharide
B) Monosaccharide
C) Polysaccharide
D) Trisaccharide
B) Monosaccharide
Which lipid makes up most of the plasma membrane?
A) Triglyceride
B) Steroid
C) Phospholipid
D) Cholesterol
C) Phospholipid
What type of bond links amino acids together?
A) Glycosidic
B) Hydrogen
C) Peptide
D) Ionic
C) Peptide
DNA uses which nitrogenous base that RNA does not?
A) Uracil
B) Thymine
C) Adenine
D) Cytosine
B) Thymine
Which cell type lacks a nucleus?
A) Eukaryote
B) Prokaryote
C) Plant cell
D) Animal cell
B) Prokaryote
Monosaccharides have what general chemical formula?
A) C₆H₁₂O₆
B) C₁₀H₂₀O₁₀
C) Cₙ(H₂O)ₙ
D) C₂H₄O₂
C) Cₙ(H₂O)ₙ
Which type of fat has double bonds between carbons?
A) Unsaturated
B) Saturated
C) Trans fat
D) Hydrogenated
A) Unsaturated
The secondary structure of proteins is stabilized by what type of bonds?
A) Hydrogen
B) Peptide
C) Ionic
D) Disulfide
A) Hydrogen
The base-pairing rule in DNA is:
A) A–G and C–T
B) A–T and C–G
C) A–C and G–T
D) A–U and C–G
B) A–T and C–G
What organelle packages and ships proteins?
A) Rough ER
B) Golgi apparatus
C) Nucleus
D) Lysosome
B) Golgi apparatus
Which of the following statements best describes starch?
A) A storage polysaccharide in animals
B) A structural polysaccharide in plant cell walls
C) A storage polysaccharide in plants made of α-glucose monomers
D) A polymer of β-glucose forming microfibrils
C) A storage polysaccharide in plants made of α-glucose monomers
What happens to membrane fluidity as phospholipids become more unsaturated?
A) It decreases
B) It increases
C) No change
D) Becomes solid
B) It increases
Which structural level of a protein involves R-group interactions and forms a 3-D shape?
A) Primary
B) Secondary
C) Tertiary
D) Quaternary
C) Tertiary
In which direction is DNA synthesized?
A) 3′ → 5′
B) 5′ → 3′
C) Both directions
D) Randomly
B) 5′ → 3′
What evidence supports the endosymbiotic origin of mitochondria and chloroplasts?
A) Both contain circular DNA and double membranes
B) Both lack ribosomes and membranes
C) Both contain linear DNA
D) Both arise spontaneously
A) Both contain circular DNA and double membranes
If a dehydration reaction links two glucose molecules, what bond forms and what molecule is lost?
A) Ionic bond; CO₂
B) Hydrogen bond; O₂
C) Glycosidic bond; H₂O
D) Peptide bond; H₂O
C) Glycosidic bond; H₂O
Which of the following correctly describes cholesterol’s dual role?
A) Makes membranes impermeable and allows for sugar binding
B) Reduces fluidity in heat and prevents rigidity in cold
C) Stores genetic info and breaks down amino acids
D) Breaks down fatty acids and facilitates respiration happy hour
B) Reduces fluidity in heat and prevents rigidity in cold
A protein exposed to extreme pH loses its function. What process occurred and why?
A) Denaturation; hydrogen and ionic bonds broke
B) Hydrolysis; peptide bonds broke
C) Oxidation; amino acids converted
D) Translation; folding failed
A) Denaturation; hydrogen and ionic bonds broke
Which part of ATP contains the highest potential energy?
A) Adenine
B) Ribose
C) Phosphate groups
D) Nitrogen base
C) Phosphate groups
What component of the cytoskeleton enables muscle contraction and pseudopod movement?
A) Microtubules
B) Intermediate filaments
C) Microfilaments (actin)
D) Centrioles
C) Microfilaments (actin)