Chapter 03 _ Cells

Cell

Cell

The basic structural and functional unit of all living organisms. Can only be seen with a microscope

Plasma Membrane

The outer boundary of a cell, composed of a phospholipid bilayer that is selectively permeable.

Cytoplasm

The internal living material of cells that fills the space between the plasma membrane and the nucleus.

Nucleus

The control center of the cell that contains DNA and regulates cell activities.

Organelles

Specialized structures within the cytoplasm that perform specific functions.

Ribosomes

Organelles that manufacture proteins, often referred to as protein factories.

Endoplasmic Reticulum (ER)

A network of sacs and canals that transport substances; includes rough ER (with ribosomes) and smooth ER (without ribosomes).

Golgi Apparatus

The chemical processing and packaging center of the cell that modifies and packages proteins.

Mitochondria

Organelles involved in energy-releasing chemical reactions, containing their own DNA.

Lysosomes

Membranous organelles containing digestive enzymes that help break down waste materials.

Centrosome

The microtubule-organizing center of the cell, containing centrioles that assist in cell reproduction.

Microvilli

Small, fingerlike extensions of the plasma membrane that increase surface area for absorption.

Cilia

Hairlike extensions on some cells that move in a coordinated manner to facilitate movement.

Flagella

Long, whip-like structures that enable movement, such as the tails of sperm cells.

Diffusion

The process by which substances scatter evenly throughout a space, moving from high to low concentration.

Osmosis

The diffusion of water across a selectively permeable membrane.

Active Transport

The movement of substances against their concentration gradient, requiring energy (ATP).

Ion Pumps

Protein complexes that use ATP to move ions across cell membranes against their concentration gradients.

Phagocytosis

A form of active transport where cells engulf large particles, often for defense against pathogens.

Pinocytosis

A form of active transport where cells take in fluids or dissolved substances.

Cystic Fibrosis

A genetic disorder caused by failed chloride ion transport, leading to thick secretions in the body.

Cholera

a bacterial infection that makes cells in the intestines lose chloride and water, leading to severe diarrhea and dehydration.

Mitosis

The process of cell division that results in two identical daughter cells, enabling reproduction and heredity.

Prophase

First stage; Chromosomes become visible, the nuclear membrane disappears, and spindle fibers form.

Metaphase

Second Stage; Chromosomes line up in the middle of the cell.

Anaphase

Third stage; Chromatids (halves of each chromosome) are pulled apart to opposite ends of the cell.

Telophase

fourth stage; New nuclear membranes form around each set of chromosomes, and the cell starts to split.

DNA

The molecule that contains the genetic code for an organism, structured as a double helix.

RNA

A molecule that plays a crucial role in protein synthesis, transferring genetic information from DNA to ribosomes.

Transcription

The process of copying a gene's DNA sequence into messenger RNA (mRNA).

Translation

The process of synthesizing proteins from mRNA at ribosomes in the cytoplasm.

Hypertrophy

An increase in the size of individual cells, leading to an increase in tissue size.

Atrophy

A decrease in the size of individual cells, leading to a decrease in tissue size.

Hyperplasia

An increase in cell reproduction, resulting in an increase in tissue size.