Chapter 2: Cell Stuff

What is the basic, living, structural, and functional unit of the body?

The cell.

What is cytology?

The study of cell structure.

What is cell physiology?

The study of cell function.

What model describes the structure of the plasma membrane?

The fluid mosaic model.

What are the three main lipid components of the plasma membrane?

Phospholipids, cholesterol, and glycolipids.

What percentage of the plasma membrane lipids are phospholipids?

75%.

What is the role of cholesterol in the plasma membrane?

Stabilizes and reduces membrane fluidity.

What is the glycocalyx?

A carbohydrate-rich layer of glycoproteins and glycolipids used for recognition, adhesion, and protection.

What are the six main functions of membrane proteins?

Channels, transporters, receptors, enzymes, linkers, and cell identity markers.

What is cytosol?

The intracellular fluid where many metabolic reactions occur.

What are the three main components of the cytoskeleton?

Microfilaments, intermediate filaments, and microtubules.

What is the function of the centrosome?

Organizes microtubules and helps with mitotic spindle formation.

What is the difference between cilia and flagella?

Cilia move substances across the cell surface, while flagella move entire cells.

What is the function of free ribosomes?

Synthesize proteins for use inside the cell.

What is the function of membrane-bound ribosomes?

Synthesize proteins for secretion or plasma membrane insertion.

What are the main functions of rough ER vs. smooth ER?

Rough ER = protein synthesis; Smooth ER = lipid synthesis, detoxification, calcium storage.

What is the main function of the Golgi complex?

Modifies, sorts, and packages proteins and lipids.

What is autophagy?

The recycling of old organelles by lysosomes.

Which organelle detoxifies alcohol and fatty acids?

Peroxisomes.

Which organelle destroys unneeded or damaged proteins?

Proteasomes.

What is the site of ATP production?

Mitochondria.

Where is DNA located inside the cell?

In the nucleus.

What are the two main categories of transport across membranes?

Passive and active transport.

Name three types of passive transport.

Diffusion, facilitated diffusion, osmosis.

What is primary active transport?

Transport that uses ATP directly (e.g., Na⁺/K⁺ pump).

What is secondary active transport?

Transport that uses ion gradients (symporters and antiporters).

What are the three types of endocytosis?

Receptor-mediated, phagocytosis, and pinocytosis.

What process moves substances out of a cell using vesicles?

Exocytosis.

What is the central dogma of molecular biology?

DNA → RNA → Protein.

What process makes RNA from DNA?

Transcription.

What process makes protein from mRNA?

Translation.

What are introns and exons?

Introns = noncoding regions removed; Exons = coding regions kept.

What molecule carries amino acids to the ribosome during translation?

tRNA.

What are the two types of cell division?

Somatic (mitosis) and reproductive (meiosis).

What are the phases of interphase?

G1 (growth), S (DNA replication), G2 (prep).

How many chromosomes do human somatic cells have?

46 chromosomes (23 pairs).

What does “diploid” mean?

Having two sets of chromosomes (2N).

What does “haploid” mean?

Having one set of chromosomes (N).

Approximately how many cells are in the human body?

~100 trillion.

How many different types of cells are there in the body?

About 200.

What is Progeria?

A genetic disorder causing short telomeres and premature aging.

What is Werner’s syndrome?

A genetic disorder that causes premature aging.

What is cancer?

A disease of uncontrolled cell proliferation.

What is the difference between benign and malignant tumors?

Benign = noncancerous; Malignant = cancerous, can metastasize.

Name one drug that blocks DNA replication in cancer therapy.

Cisplatin or Doxorubicin.

Name one drug that blocks microtubule formation in cancer therapy.

Taxol.

What is angiogenesis?

Formation of new blood vessels (important in wound healing and cancer).