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7-2 Eukaryotic Cell Structure

I. Parts of the Cell

A. Nucleus -control center of the cell -contains DNA -Parts of the nucleus Chromatin-granular material

visible inside the nucleus, forms chromosomes during cell division

Nucleolus - inside nucleus, makes ribosomes

Nuclear envelope - surrounds nucleus, contains nuclear pores

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B. Ribosomes -assemble

proteins -located on the

endoplasmic reticulum and also floating in cytoplasm

Ribosomes

C.  Endoplasmic Reticulum (ER) 1. Rough ER - modify proteins, assemble cell membrane parts, move proteins to golgi apparatus 2. Smooth ER - no ribosomes, detoxification & synthesis of membrane lipids

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D. Golgi Apparatus - modify, sort & package proteins

from the ER - ships proteins where they are

needed in the cell

E. Lysosomes - break down lipids, carbs, &

proteins - digest old cell parts - “garbage disposals”

F. Vacuoles - used for storage of water, salt, & proteins

Vacuole

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G.  Choloroplasts - plants only -contain chlorophyll -capture sun-light to carry out photosynthesis -have their own DNA

Chloroplast

Chloroplast

H.  Mitochondria - use food energy to make compounds for growth, development & movement - have their own DNA - “powerhouse” of the cell

Mitochondrion

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II. Support - Cytoskeleton

!  Maintain cell shape & aid in movement !  Made of 2 kinds of protein

–  Microtubules !  Hollow tubes of protein !  Separate chromosomes during cell division !  Make up cilia & flagella

–  Microfilaments !  Long, thin fibers !  Form a flexible network to move organelles around

Cytoskeleton !  Cytoskeleton

Ribosomes Mitochondrion

Endoplasmic reticulum

Cell membrane

Microtubule

Microfilament