Cell Structure and Function

Prokaryote bacteria cells Eukaryote animal cells Types of cells Prokaryote bacteria cells Eukaryote animal cells Eukaryote plant cells

Cell characteristics All cells: are surrounded by a plasma membrane have cytoplasm cytoplasm = cytosol + organelles contain DNA have ribosomes tiny “organelles” that make proteins using instructions contained in genes

Eukaryotes Prokaryotes DNA Associated with protein in membrane-bound nucleus single circle. “naked” Size 5-100 µm 0.2-10 µm Organization Single and multicellular, some have cell walls single-celled, all have cell walls Division Mitosis and Meiosis Binary Fission Organelles membrane bound organelles like mitochondria no organelles, different ribosomes (70S) Examples plants, animals, protists, fungi bacteria, archaea 4 4

Eukaryotic - Animal Cell

Eukaryotic - Plant Cell

2.2.1 2.2.2 Prokaryotic Cell

E. coli ultrastructure (SEM) 2.2.3 E. coli ultrastructure (SEM)

Prokaryotic Cells divide by binary fission 2.2.4

Representative Animal Cell 10

Drawing of animal cell. 2.3.1 and 2.3.2

Representative Plant Cell 12

Liver Cell (SEM) 2.3.3

Animal Plant Cell Wall Chloroplasts Polysaccharides Vacuole Shape 2.3.4 Cell Wall No, only plasma membrane Yes, and plasma membrane Chloroplasts no yes Polysaccharides Glycogen Starch as storage Cellulose for structure Vacuole Large fluid filled present Shape Able to change shape. Usually rounded. Fixed shape. Usually regular. 14 14

Cell Membrane Structure: Function: phospholipid bilayer proteins that function as channels, markers, and receptors. Function: selectively permeable boundary between the cell and external environment 15

Nucleus Structure: Function: membrane bound sphere that contains DNA and nucleolus Function: storage center of cell’s DNA manages cell functions 16

Cell Wall Structure: Function: Rigid wall made up of cellulose, proteins, and carbohydrates Function: Permeable boundary around the outside of the plant cell membrane that provides structure and support 17

Cytoskeleton Structure: Function: a network of thin, fibrous elements made up of microtubules and microfilaments Function: acts as a support system for organelles maintains cell shape 18

Ribosomes Structure: Function: consist of two subunits made of protein and RNA Function: location of protein synthesis 19

Endoplasmic Reticulum Structure: a system of membranous tubules and sacs Function: intercellular highway (a path along which molecules move from one part of the cell to another) 20

Rough Endoplasmic Reticulum Rough Endoplasmic Reticulum (rER): prominent in cells that make large amounts of proteins to be exported from the cell Covered with ribosomes 21

Smooth Endoplasmic Reticulum Smooth Endoplasmic Reticulum (sER): involved in the synthesis of lipids and breakdown of toxic substances Not covered with ribosomes 22

Golgi Apparatus Structure: Function: stacked flat sacs receives vesicle bound proteins from the rER and distributes them to other organelles or out of the cell receiving, processing, packaging, and shipping AKA: Golgi body, Golgi complex or dictysome 23

Lysosomes Structure: Function: spherical organelles that contain digestive (hydrolytic) enzymes Function: breaks down food particles, invading objects, or worn out cell parts 24

Vacuoles Structure: Function: a sac of fluid surrounded by a membrane used for temporary storage of wastes, nutrients, and water 25

Mitochondria Structure: Function: folded membrane (cristae) within an outer membrane. Function: converts energy stored in food into usable energy (ATP) Allows aerobic cellular respiration 26

Chloroplasts Structure: Function: stacked sacs (thylakoids) that contain chlorophyll surrounded by a double membrane Function: photosynthesis (conversion of light energy to chemical energy stored in the bonds of glucose) 27

Mitochondria & Chloroplasts Lynn Margulis U of M, Amherst Mitochondria & Chloroplasts Important to see the similarities transform energy generate ATP double membranes = 2 membranes semi-autonomous organelles move, change shape, divide internal ribosomes, DNA & enzymes

Evolution of eukaryotes Endosymbiosis theory Evolution of eukaryotes

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