SuperQuiz2 Flashcards

What are the three main elements (fibers) of the cytoskeleton?

Microfilaments (Actin), Intermediate Filaments, Microtubules.

What are the components associated with microfilaments?

Actin monomers, Dynamic, Myosin, Muscle contraction/movement.

What is the motor protein associated with microfilaments and what movement does it facilitate?

Myosin; Muscle contraction.

What protein are microtubules made of?

Tubulin.

What proteins are associated with each cytoskeleton element?

Microfilaments: Actin, Myosin; Intermediate Filaments: Various proteins like keratin; Microtubules: Tubulin, Kinesin, Dynein.

What are the types of cell junctions and their functions?

Tight Junctions: Seal spaces between cells, prevent leakage; Adherens Junctions: Connect actin cytoskeletons via cadherins; Desmosomes: Provide mechanical strength, link intermediate filaments; Gap Junctions: Allow communication via ion and molecule passage.

What are Cadherins?

Cell adhesion molecules, responsible for cell sorting in tissues.

Why do cells of the same tissue type sort themselves out when mixed with cells from another tissue?

Due to specific cadherins on their surface that promote adhesion to cells of the same type.

What are the layers that make up the extracellular layer of plants?

Primary Cell Wall: Flexible, composed of cellulose; Secondary Cell Wall: More rigid, contains lignin; Middle Lamella: Pectin-rich, glues cells together.

What are the major components of the animal cell extracellular matrix?

Collagen, Proteoglycans, Fibronectin, Laminin.

What is the Basal Lamina and what does it support?

A specialized extracellular matrix that supports epithelial and endothelial cell layers.

Describe the structure of collagen.

A strong, fibrous protein with a triple helix structure.

Define Anabolic.

Metabolic pathways that consume energy to build complex molecules from simpler ones.

Define Catabolic.

Metabolic pathways that release energy by breaking down complex molecules into simpler compounds.

What is the general function of enzymes?

Biological catalysts that speed up biochemical reactions by lowering activation energy.

What binds to the active site of an enzyme?

Substrate.

What type of biomolecule are most enzymes?

Proteins.

What is activation energy?

The energy required to reach the transition state of a reaction.

What is a cofactor?

A non-protein chemical compound or metallic ion that is required for an enzyme's activity as a catalyst.

How do pH and temperature affect an enzyme?

Enzymes have optimal pH and temperature ranges for activity; outside these ranges, activity decreases.

How do enzymes physically work with the substrate?

The enzyme's active site binds to the substrate, forming an enzyme-substrate complex.

How do amino acid side chains (R-groups) in the active site affect substrate binding?

R-groups can interact with the substrate through various chemical bonds, influencing binding specificity and catalysis.

How can exergonic reactions drive endergonic reactions?

Through energetic coupling, where the energy released by an exergonic reaction is used to power an endergonic reaction.

How does change in free energy relate to energetically coupled reactions?

The overall change in free energy for the coupled reaction must be negative for the reaction to be spontaneous.