HUMAN BIOLOGY

What is diffusion in the context of cell transport methods?

Movement of molecules from an area of higher concentration to an area of lower concentration.

What is osmosis?

Diffusion of water molecules across a selectively permeable membrane.

How does facilitated diffusion differ from regular diffusion?

Facilitated diffusion involves movement across a membrane via transport proteins, without energy input.

What is active transport and what does it require?

Movement of molecules against a concentration gradient, requiring energy in the form of ATP.

What is endocytosis?

Process by which cells engulf external substances, bringing them into the cell.

What happens during exocytosis?

Cells expel materials in vesicles to the outside environment.

What is the primary function of the nucleus?

Acts as the control center of the cell, housing DNA and regulating gene expression.

Why are mitochondria referred to as the powerhouses of the cell?

They generate ATP through cellular respiration.

What is the main role of ribosomes?

Sites of protein synthesis, translating genetic instructions from mRNA to build proteins.

What is the difference between rough ER and smooth ER?

Rough ER is studded with ribosomes and assists in protein synthesis; Smooth ER is involved in lipid synthesis, detoxification, and calcium storage.

What does the Golgi apparatus do?

Modifies, sorts, and packages proteins and lipids for secretion or use within the cell.

What role do lysosomes play in a cell?

Contain digestive enzymes to break down macromolecules, old cell parts, and foreign invaders.

What functions do peroxisomes serve?

Break down fatty acids and amino acids and detoxify poisons.

What is the function of chloroplasts in plant cells?

Sites of photosynthesis, converting solar energy into chemical energy stored in glucose.

What do vacuoles do?

Storage organelles that can contain water, nutrients, or waste.

What is the main purpose of the cell membrane?

Selectively permeable barrier that regulates what enters and exits the cell.

List two functions of the cytoskeleton.

Provides structural support for the cell; involved in cell movement and transport of materials within the cell.

What are the key functions of the cell membrane?

Protective barrier, selective permeability, signal reception and transmission, cell adhesion, enzymatic activity, and attachment point.