Review Questions Exam 1 BIOL 3300

What are the properties of living organisms?

Organization, metabolism, homeostasis, growth and development, reproduction, response to stimuli, adaptation.

What is the cell theory?

1. All living organisms are composed of one or more cells. 2. The cell is the basic unit of life. 3. All cells arise from pre-existing cells.

Who was the first scientist to identify cells and what type of cells did he observe?

Robert Hooke observed dead plant cells in a slice of cork.

What are the two types of cells?

Prokaryotic Cells and Eukaryotic Cells.

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells lack a nucleus and membrane-bound organelles; eukaryotic cells have a nucleus and organelles.

What are model organisms?

Non-human species that are studied to understand biological phenomena; easy to maintain and breed.

Give examples of model organisms and their uses.

E. coli for basic cellular processes, yeast for cell cycle studies, fruit flies for genetics, C. elegans for development, and Mus musculus for mammalian studies.

What is the basic structure of an atom?

An atom consists of a nucleus containing protons and neutrons, with electrons orbiting in shells.

What does atomic number represent?

The number of protons in the nucleus of an atom.

What is atomic mass?

The total number of protons and neutrons in the nucleus.

Why do atoms interact with one another?

To achieve a more stable electron configuration.

What types of atomic interactions exist?

Covalent Bonds, Ionic Bonds, Hydrogen Bonds, Van der Waals Forces.

Define organic compounds.

Molecules containing carbon atoms bonded to hydrogen atoms, often with other elements like oxygen and nitrogen.

What are the common types of organic compounds in living organisms? (what are the 4 macromolecules)

Carbohydrates, Lipids, Proteins, Nucleic Acids.

What is the structure of carbohydrates?

Composed of carbon, hydrogen, and oxygen atoms, typically in a ratio of 1:2:1.

List the functions of lipids.

Store energy, make up cell membranes, and act as signaling molecules.

What is the primary structure of proteins?

The sequence of amino acids in a polypeptide chain.

How are polymers formed?

Through dehydration synthesis, where monomers are joined by covalent bonds with the removal of water.

What are the types of metabolic pathways?

Catabolic pathways break down molecules, anabolic pathways build complex molecules.

Describe favorable reactions in terms of ∆G.

favorable reactions are exergonic and have a negative ∆G value, meaning they release energy and occur spontaneously.

What influences the ∆G of a reaction?

The ratio of reactants to products

How are proteins synthesized?

Proteins are synthesized from amino acids linked by peptide bonds, with the order specified by DNA.

How do amino acids form polypeptide chains?

Through peptide bonds formed by dehydration synthesis.

What interactions stabilize protein structure?

Hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges.

What are protein domains?

Distinct functional/structural units within proteins that can fold independently.

Where are hydrophobic amino acids located in a protein?

Hydrophobic amino acids are usually found in the interior of a folded protein.

What are methods used to determine protein structure?

X-ray Crystallography, NMR Spectroscopy, Cryo-Electron Microscopy.

How do proteins perform their functions?

by binding to other molecules to induce conformational changes.

What is a ligand in protein interactions?

A molecule that binds to proteins through noncovalent interactions.

Describe the structure of antibodies.

Y-shaped molecules made of two heavy and two light chains; variable regions at the tips bind specific antigens.

What is Vmax in enzyme kinetics?

The maximum rate of an enzyme-catalyzed reaction when the enzyme is fully saturated with substrate.

What does Km indicate in enzyme kinetics?

The substrate concentration at which the reaction rate is half of Vmax, reflecting enzyme affinity.

What role does lysozyme play in the immune system?

Lysozyme catalyzes the breakdown of bacterial cell walls, aiding the immune response.

How do cells regulate protein activity?

Through allosteric regulation, phosphorylation, proteolytic cleavage, feedback inhibition, and protein-protein interactions.