Cell Basics & Structure

Cell theory

All living things are made of cells; cells are the smallest unit of life; cells come from preexisting cells

Common features of all cells

Genetic information, ability to use energy, regulation of activities, response to stimuli

Prokaryotic cell

Cell without membrane-bound organelles; DNA in nucleoid; examples: bacteria, archaea

Eukaryotic cell

Cell with membrane-bound organelles; examples: animals, plants, fungi, protists

Organelles

Internal membrane-bound compartments in eukaryotic cells with specialized functions

Examples of prokaryotes

Bacteria, archaea

Examples of eukaryotes

Yeast, plants, animals, fungi

Nucleus

Control center of cell; contains DNA and regulates gene expression

Nuclear envelope

Double membrane surrounding nucleus; isolates DNA from cytoplasm

Nuclear pores

Allow large molecules (proteins, RNA) to pass in and out with help of proteins

Nucleolus

Structure inside nucleus responsible for ribosome assembly

Mitochondria

Powerhouse of cell; converts glucose into ATP

ATP

Adenosine triphosphate; main energy currency of cell

Unique features of mitochondria

Own DNA, ribosomes, inner/outer membranes, matrix

Rough ER

Endoplasmic reticulum studded with ribosomes; site of protein synthesis

Smooth ER

Endoplasmic reticulum without ribosomes; makes lipids, stores substances, detoxifies

Golgi apparatus

Processes, modifies, and packages proteins for secretion or use inside cell

Cis face of Golgi

Receiving side of Golgi apparatus (from ER)

Trans face of Golgi

Shipping side of Golgi apparatus (to cell or outside)

Vesicle

Membrane-bound sac that stores and transports molecules

Lysosome

Vesicle containing enzymes that break down waste, foreign material, and dead cells

Peroxisome

Vesicle that breaks down fatty acids and toxins

Ribosome

Protein synthesis site; made of RNA + proteins; found free or on rER

Cytoplasm

Cell contents outside nucleus; includes cytosol, organelles, and molecules