Cell structure and function Cell Organelles Organelles small

Cell structure and function

Cell Organelles • Organelles: small structures within cells that carry out various functions • STRUCTURE DETERMINES FUNCTION • Surface Area – greater surface area provides for more productivity • FOLDS!!!

Organelles • Nucleus: houses genetic material • Ribosomes: make proteins using genetic information from the • Nuclear Membrane/Envelope: nucleus, 2 subunits surrounds and protects genetic material • Nuclear Pores: holes in the nuclear membrane • Nucleolus: dense region; ribosomal subunits • Chromatin: genetic material

Organelles • Endoplasmic Reticulum: folded membrane system surrounding nucleus; stores and transmits lipids and proteins throughout cell

Organelles • Golgi Apparatus: modifies, prepares proteins and lipids to send out of cell

Organelles • Mitochondria: site of cellular respiration; converts food energy (glucose) into cell energy (ATP) • Very FOLDED inner-membrane: cristae!

Organelles • Chloroplast: site of photosynthesis; converts light energy into glucose • PLANTS!

Organelles • Lysosomes: break down organic molecules and digest worn-out cell parts

Organelles • Vacuole: • Storage for water, organic molecules, salts, etc. • **Large in plants!

Cell Parts • Cytoskeleton: • A network of proteins that help cell maintain shape. • Microtubules: Thin, hollow cylinders of protein. • Microfilaments: Thin, solid protein fibers. • Cilia and Flagella: • Cilia: Short, numerous, hair-like projections from the plasma membrane of the cell. • Often beat synchronously to produce motion. • Flagella: Long projections that move in a whip-like motion to produce movement. • The major method of locomotion in unicellular organisms. • Found mainly in bacteria and Protists • Sperm cells!

Structures for Locomotion 11

Structures for Locomotion 12

Cytoplasm • Fluid-filled space surrounding organelles

Surrounding the Cell Plasma Membrane/Cell Membrane: • phospholipid bilayer • Fluid mosaic model • membrane that surrounds ALL cells • Regulates what enters and leaves; Semipermeable! • Permeable to lipids, nonpolar and smaller substances • Maintains solution concentrations! • Contains Transport Proteins • Embedded in membrane; help certain substances move into or out of cell

The Plasma Membrane Structure 15

Surrounding the Cell • Cell Wall: made of cellulose, helps maintain structure • PLANTS, Fungi, Prokaryotes, Algae