3.2 - The Cytoplasm and Cellular Organelles

Cytosol

Jelly-like substance within the cell, provides the fluid medium necessary for biochemical reactions

Cytoplasm

The organelles and cytosol

Nucleus

Contains DNA; contains the nucleolus (site of ribosome production); site of transcription; surrounded by the nuclear envelope

Endoplasmic Reticulum (ER)

Site of synthesis of fats, hormones, secreted proteins, and membrane proteins; sugar modification of proteins

Ribosome

Site of protein synthesis; free ribosomes in the cytoplasm synthesize soluble proteins; ER-bound ribosomes synthesize proteins for secretion or membranes

Golgi Apparatus

Sorts proteins from the ER to membranes or secretion; performs additional sugar modification of proteins

Lysosome

Site for degradation of proteins (protein turnover)

Autophagy

Process of a cell digesting its own structures.

Autolysis

Makes the process of cell death controlled (a mechanism called “apoptosis”)

Mitochondria

Organelles that produce ATP through cellular respiration

Peroxisome

Involved in lipid metabolism and detoxification of harmful substances (alcohol, reactive oxygen species)

Mutation

Change in the nucleotide sequence in a gene within a cell’s DNA, potentially altering the protein coded by that gene.

Cytoskeleton

Maintains cell shape and structure; promotes cellular movement and division - components: microtubules (cilia, flagella, centrioles), microfilaments (actin fibers in muscle), and intermediate filaments (keratin in skin)

Microtubule

A structural filament composed of subunits of a protein called tubulin

Cilia

Found on many cells of the body, including the epithelial cells that line the airways of the respiratory system

Flagellum

An appendage larger than a cilium and specialized for cell locomotion

Centriole

Cellular origin point for microtubules extending outward as cilia or flagella or can assist with the separation of DNA during cell division.

Microfilament

A thinner type of cytoskeletal filament

Intermediate Filament

A filament intermediate in thickness between the microtubules and microfilaments

Nucleolus

Located within the nucleus; site of ribosome production and assembly

Nuclear Envelope

Double membrane surrounding the nucleus; contains nuclear pores for regulated transport