Elements of Life - AP Biology

What is the function of ATP in the cell?

Energy currency of the cell. Stores and transfers energy through high-energy phosphate bond hydrolysis.
What are the four most common elements in living organisms?

Carbon, hydrogen, oxygen, nitrogen. These four elements form the backbone of all major biological macromolecules.
Which macromolecule can function as enzymes?

Proteins. Complex three-dimensional structure enables catalytic and regulatory functions.
Which type of bond holds the two strands of DNA together?

Hydrogen bonds. Weak bonds between complementary base pairs maintain double helix structure.
Identify the monomer of proteins.

Amino acids. Individual units that link together via peptide bonds to form protein chains.
Identify the element that is a key component of chlorophyll.

Magnesium. Central metal ion in chlorophyll molecule essential for photosynthesis.
Which vitamin is essential for calcium absorption?

Vitamin D. Promotes intestinal calcium absorption and bone mineralization processes.
What element is central to all organic molecules?

Carbon. Forms four covalent bonds, creating the backbone of biological molecules.
What are the building blocks of lipids?

Glycerol and fatty acids. Three-carbon alcohol backbone with fatty acid chains attached forms lipid structure.
Identify the amino acid that contains sulfur.

Cysteine. Only amino acid containing sulfur, forms disulfide bonds in proteins.
State the chemical formula for glucose.

$C_6H_{12}O_6$ . Simple sugar with 6 carbons, 12 hydrogens, and 6 oxygens in its molecular structure.
Which element is a key component of hemoglobin?

Iron. Central atom in heme group that binds oxygen for transport.
Identify the type of reaction that forms peptide bonds.

Dehydration synthesis. Water molecule removal creates covalent bonds between amino acid residues.
Which type of RNA carries amino acids to the ribosome?

tRNA. Transfer RNA delivers specific amino acids to growing polypeptide chains.
Identify the type of sugar found in RNA.

Ribose. Five-carbon sugar component of RNA nucleotides, unlike DNA's deoxyribose.
What is the main role of cholesterol in the cell membrane?

Stabilize membrane fluidity. Maintains optimal membrane viscosity across different temperature conditions.
Which bond type is primarily responsible for the secondary structure of proteins?

Hydrogen bonds. Stabilizes alpha helices and beta sheets in protein folding patterns.
Which type of bond forms between water molecules?

Hydrogen bond. Weak attraction between hydrogen and oxygen atoms creates water's unique properties.
What type of macromolecule are antibodies?

Proteins. Complex protein structures that recognize and neutralize foreign antigens.
What is the role of nucleic acids in cells?

Store and transmit genetic information. DNA and RNA carry hereditary instructions and enable protein synthesis.
Identify the monomer of nucleic acids.

Nucleotides. Individual units containing sugar, phosphate, and nitrogenous base components.
Identify the sugar found in DNA.

Deoxyribose. Five-carbon sugar lacking one hydroxyl group compared to ribose.
Which macromolecule is responsible for storing energy long-term?

Lipids. High energy density makes fats ideal for extended energy storage needs.
What is the primary function of the rough endoplasmic reticulum?

Protein synthesis. Ribosomes attached to ER translate proteins destined for secretion or membranes.
Which element is found in the structure of ATP?

Phosphorus. Essential component of phosphate groups in ATP's energy-storing bonds.
What is the function of the mitochondrial matrix?

Site of the Krebs cycle. Inner compartment where citric acid cycle reactions occur during respiration.
Which type of carbohydrate is a primary energy source?

Monosaccharides. Simple sugars like glucose are rapidly metabolized for immediate energy.
Identify the primary structure of proteins.

Sequence of amino acids. Linear arrangement of amino acids determines all higher-level protein structures.
What is the major function of hemoglobin in the body?

Transport oxygen in the blood. Iron-containing protein carries oxygen from lungs to body tissues.
What is the main structural component of plant cell walls?

Cellulose. Complex polysaccharide providing structural rigidity and protection to plant cells.
What is the process of protein synthesis called?

Translation. Process where ribosomes read mRNA to assemble amino acids into proteins.
What is the function of glycogen in animals?

Short-term energy storage. Branched glucose polymer stored in liver and muscle for quick energy.
What is the chemical formula for water?

$H_2O$ . Two hydrogen atoms bonded to one oxygen atom form this essential compound.
Identify the type of lipid that is a major component of cell membranes.

Phospholipids. Amphipathic molecules that self-assemble into cellular membrane bilayers.
Which macromolecule serves as the main component of cell membranes?

Phospholipids. Amphipathic molecules with hydrophilic heads and hydrophobic tails form bilayers.
What are the components of a nucleotide?

Sugar, phosphate group, nitrogenous base. Basic building blocks that link together to form nucleic acid chains.
Identify the molecule that acts as a messenger carrying instructions from DNA.

mRNA. Transfers genetic information from nucleus to ribosomes for protein synthesis.
Identify the bond that links nucleotides in DNA.

Phosphodiester bond. Covalent bond between phosphate and sugar creates DNA's sugar-phosphate backbone.
What is the function of enzymes in biological reactions?

Catalysts that speed up reactions. Lower activation energy by binding substrates and stabilizing transition states.
What is the primary function of carbohydrates in cells?

Energy storage and supply. Carbohydrates like glucose provide immediate fuel for cellular processes.

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