Introduction to Animal Cells Characteristics of Animal Cells

Introduction to Animal Cells

Characteristics of Animal Cells • They are eukaryotic cells, that means they contain a membrane bound nucleus • They lack a cell wall that plant cells have • Generally they are larger and more complex than prokaryotic cells • Contains membrane bound structures called organelles

Plasma Membrane • Not an organelle • Selectively permeable • Defines boundaries of cell and ensures contents are retained • Made of proteins and lipids – Phospholipid bilayer

Nucleus • Considered the “Control Center” of the cell • Controls cell activity • Contains nearly all of the cell’s DNA

Nucleolus • Small, dense region within the nucleus • The beginning site of protein assembly

Nuclear Envelope • • Double membrane that surrounds nucleus Protects and isolates cell DNA Selectively permeable Contains thousands of nuclear pores that allow material to move into and out of the cell

Centrioles • Located near the nucleus • Help to organize cell division in animal cells

Ribosomes • Most numerous and smallest organelle • Composed of RNA and proteins • Found throughout cytoplasm and attached to Rough Endoplasmic Reticulum • Site of protein synthesis • Made of 2 subunits

Endoplasmic Reticulum (ER) • Site where lipid components of cell membrane and proteins are assembled • Site of preparation of material to be exported from the cell • Two types – Rough ER – Smooth ER

Endoplasmic Reticulum cont. • Rough ER • Smooth ER – Has ribosomes attached to surface – Portion of ER involved in protein synthesis – Lacks ribosomes – Contains enzymes that are specialized detoxify drugs and synthesize membrane lipids

Golgi Apparatus • Site of protein processing, sorting, packing, and transport from ER to be secreted from the cell

Mitochondria • One of the largest organelles • Breaks down sugar molecules stored in food and converts them to chemical energy for use by the cell (ATP) • Contain their own DNA, RNA, and ribosomes and are able to reproduce themselves

Mitochondria • The “powerhouse” of the cell cont

Lysosomes & Peroxisomes • Similar in both structure and function • Lysosomes – Filled with enzymes to breakdown and digest dead organelles and proteins not being used • Peroxisomes – Detoxifies hydrogen peroxide and other harmful compounds – Plays a part in the oxidative breakdown of fatty acids in animal cells

Vacuoles • Saclike structure • Storage area for the cell • Stores materials like water, salt, proteins and carbohydrates

Cytoskeleton • Network of protein filaments that help cell maintain its shape • Involved in movement of cells