Inside the World of Cells Unit 3: Cells Chapter 7: Cell Structure and Function Section 7-2 Eukaryotic Cell Structure Text: pages 174-181

Endoplasmic reticulum Vocabulary Organelle Cytoplasm Nuclear envelope Chromosome Nucleolus Endoplasmic reticulum Golgi apparatus Lysosome Vacuole Mitochondria Chloroplast Cytoskeleton Centriole

Introduction Organelles: structures found in eukaryotes that act as specialized organs. 2 major parts of the cell Nucleus Cytoplasm

Nucleus Control center of the cell Contains cell’s DNA Surrounded by nuclear envelope Pores allow material to move in and out Chromatin Chromosomes Nucleolus: where ribosome assembly begins.

Ribosomes Where proteins are made- proteins are assembled on ribosomes. Ribosomes: small particles of RNA and protein found throughout the cytoplasm Instructions come from nucleus to produce the proteins.

Endoplasmic Reticulum Internal membrane system Assembly of lipids, proteins, and other materials which are exported. Rough ER: involved in protein synthesis; ribosomes on surface. Smooth ER: specialized enzymes Synthesizing lipids for membranes Detoxification of drugs

Golgi Apparatus Proteins move onto the golgi apparatus. Stack of membranes- look like flattened pancakes. Golgi apparatus: modifies and packages proteins for storage in or secretion outside of cell.

Lysosomes Small and filled with enzymes Lysosomes: digest and breakdown macromolecules into small units to be used by cell. Breakdown organelles that have died Remove junk from inside the cell

Vacuoles Sac like structures Store water, salts, proteins, and carbs. Turgor Pressure Plants and some single celled organisms. Paramecium- contractile vacuole-pumps water out.

Energy in Cells Cells acquire energy in one of two ways From the food we eat- digestion From the sun- photosynthesis

Mitochondria Take energy stored in food and make it more useful to the cell. ATP Outer and inner membrane Inner is folded up inside. Mitochondria come from the egg cell- passed from out mothers.

Chloroplasts Plants and blue-green algae Photosynthesis= Capturing sun’s energy & converting into chemical energy. 2 membranes Inside are chlorophyll containing membranes

Both mitochondria and chloroplasts contain their own genetic information in the form of small DNA molecules. Descendents of early prokaryotes?????

Cytoskeleton Provides cellular support Protein filaments help maintain cell’s shape. Also involved in movement 2 types of protein filaments Microfilaments Microtubules

Microfilaments Threadlike Protein = actin Create a tough but flexible framework What allow amoebas to move or glide

Microtubules Hollow Protein = tubulin Maintains cell shape Important during cell division Cilia and flagella