PATHO CHAPTER 2

What are the 3 main functional parts of a cell?

The nucleus + cytoplasm + cell membrane.

Nucleus main function = ?

Cell control center → contains DNA

Nuclear envelope = ?

Membrane around nucleus → protects DNA

Nuclear pores = ?

Openings in nuclear envelope → control what enters/leaves nucleus

Chromatin = ?

Loose DNA + proteins → contains genetic instructions

Nucleolus = ?

A structure inside the nucleus → Makes ribosomes

3 types of RNA?

mRNA → carries instructions
rRNA → makes up ribosomes
tRNA → brings amino acids

Protoplasm = ?

Living cell material → water + proteins + electrolytes

What are the 2 regions of protoplasm?

Cytoplasm + nucleoplasm

Cytoplasm vs. nucleoplasm?

Cytoplasm → outside nucleus
Nucleoplasm → inside nucleus

What substances are found in the cytoplasm?

Cell workspace → contains water, electrolytes, proteins, fats, glycogen, and organelles

Ribosomes = ?

Protein synthesis

Rough ER = ?

Has ribosomes → makes/transport proteins

Smooth ER = ?

Makes lipids + helps detoxify substances

Golgi complex = ?

Modifies, packages, and ships proteins

Mitochondria = ?

Makes ATP → cell energy

Lysosomes = ?

Digest waste + worn-out cell parts

Proteasomes = ?

Break down damaged or unneeded proteins

Cell membrane = ?

Selective barrier → controls what enters/leaves cell

Main cell-membrane components?

Lipids + cholesterol + proteins

Lipid bilayer = ?

Double phospholipid layer → semipermeable barrier

Amphipathic?

Having one part attracted to water and one part repelled by water.

Phospholipid head vs. tail?

Head → hydrophilic → attracted to water
Tail → hydrophobic → repels water

Cholesterol does what in the membrane?

Helps stabilize membrane fluidity

Integral proteins = ?

Span the membrane → often act as channels or carriers

Peripheral proteins = ?

Attached to inner/outer membrane surface → help with signaling and support

Glycocalyx = ?

Cell surface coating → cell recognition + adhesion

A student says the cell membrane is made only of lipids and cholesterol. Is this true?

No. The cell membrane also contains proteins.

3 important functions of the cell membrane?

Receptors for hormones
Electrical activity in nerves/muscles
Regulates growth and proliferation

What is the cytoskeleton?

A network of protein structures that supports the cell’s shape and movement.

Microtubules = ?

Tubulin structures → maintain cell shape + move materials inside cell

Microtubules also form what?

Cilia, flagella, centrioles, and basal bodies

Microfilaments = ?

Thin cell fibers → support shape + help muscle contraction

Actin + myosin → function?

Muscle contraction

Autocrine signaling = ?

Cell releases signal → acts on itself

Paracrine signaling = ?

Cell releases signal → acts on nearby cells

Endocrine signaling = ?

Hormones travel in blood → act on distant cells

Synaptic signaling = ?

Neurotransmitter crosses synapse → acts on adjacent nerve cell

A hormone is released into the bloodstream and affects a distant organ. What type of signaling is this?

Endocrine signaling

Ligand = ?

Chemical messenger that binds a receptor

Ion channel–linked receptor = ?

Signal opens/closes ion channel → rapid nerve or muscle response

G-protein–linked receptor = ?

Receptor acts like on/off switch → starts signal pathway

Enzyme-linked receptor = ?

Protein hormone binds → activates enzyme activity inside cell

Intracellular receptor = ?

Ligand crosses membrane → binds receptor inside cell

First messenger = ?

Signal outside cell → hormone, neurotransmitter, growth factor, or steroid

Second messenger = ?

Signal inside cell → carries message after receptor is activated

Which three receptor classes are on the cell surface?

G-protein-linked, enzyme-linked, and ion channel-linked receptors.

Where do hydrophilic and lipophilic signals bind?

Hydrophilic signals bind the surface; lipophilic signals bind inside cells

Cell Cycle and Metabolism

Interphase = ? START HERE

What occurs in G0, G1, S, G2, and M?

Rest; growth; DNA replication; preparation; mitosis.

How do mitosis and meiosis differ?

Mitosis makes identical body cells; meiosis makes reproductive cells.

Differentiate catabolism, anabolism, and ATP.

Catabolism breaks down; anabolism builds; ATP transfers energy.

Which processes are passive?

Diffusion, osmosis, and facilitated diffusion; none require cellular energy.

Passive transport?

Movement of substances across the membrane without using cellular energy.

Diffusion?

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

Osmosis?

Movement of water across a semipermeable membrane.

Facilitated diffusion?

Passive movement of substances through a carrier protein or channel from high to low concentration.

Active transport?

Movement of substances across the membrane using energy, usually against a concentration gradient.

How do primary and secondary active transport differ?

Primary directly uses ATP; secondary uses another ion's gradient.

What does the sodium-potassium ATPase pump move?

Three sodium ions out and two potassium ions into the cell.

Differentiate endocytosis, phagocytosis, and exocytosis.

Endocytosis brings in (forms vesicle); phagocytosis engulfs debris; exocytosis releases.

Which stimuli open gated ion channels?

Voltage change, ligand binding, or mechanical force.

What creates a resting membrane potential?

Unequal ion distribution makes the cell interior negative at rest

Which four basic tissue types form the body?

Epithelial, connective, muscle, and nervous tissue.

Which features describe epithelial tissue?

It covers and lines, is avascular, and attaches to a basement membrane.

Which tissue contains actin and myosin for contraction?

Muscle tissue: skeletal, cardiac, and smooth.

What are the main roles of connective and nervous tissue?

Connective supports; nervous tissue controls and communicates.

Which epithelial junctions block, anchor, or communicate?

Tight junctions block; adhering junctions anchor; gap junctions communicate.

What makes up the extracellular matrix?

Proteoglycans and fibrous proteins such as collagen, elastin, fibronectin, and laminin.