BELLRINGER MAKE A QUICK DRAWING OF A PLANT OR ANIMAL CELL IN THE BELLRINGER SECTION OF YOUR NOTEBOOK. USE PG OF YOUR TEXTBOOK TO HELP YOU. LABEL THE PARTS.

Cells

Definition of Cell A cell is the smallest unit that is capable of performing life functions.

Examples of Cells Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria

5 Cell Theory Cells were discovered in 1665 by Robert Hooke. Early studies of cells were conducted by - Mathias Schleiden (1838) - Theodor Schwann (1839) Schleiden and Schwann proposed the Cell Theory.

Cell Theory All organisms are composed of one or more cells. Cells are the smallest living units of all living organisms. Cells arise only by division of a previously existing cell.

Two Types of Cells ProkaryoticProkaryotic EukaryoticEukaryotic

Prokaryotic Do not have structures surrounded by membranes Few internal structures One-celled organisms, Bacteria

Prokaryotic Cell Structure Prokaryotic Cells are smaller and simpler in structure than eukaryotic cells. Prokaryotic cells do NOT have: Prokaryotic cells do NOT have:Nucleus Membrane bound organelles

Prokaryotic Cell Structure Structures Plasma membrane Plasma membrane Cell wall Cell wall Cytoplasm with ribosomes Cytoplasm with ribosomes Nucleoid Nucleoid Capsule* Capsule* Flagella* and pili* Flagella* and pili* *present in some, but not all prokaryotic cells

Eukaryotic Contain organelles surrounded by membranes Most living organisms PlantAnimal

Eukaryotic Cells Structures in all eukaryotic cells Nucleus Nucleus Ribosomes Ribosomes Endomembrane System Endomembrane System Endoplasmic reticulum – smooth and rough Golgi apparatus Vesicles Mitochondria Mitochondria Cytoskeleton Cytoskeleton

Eukaryotic Cells Eukaryotic cells include plant and animal cells. Most Eukaryotes are multicellular. REMEMBER: The difference between a plant and animal cell is that a plant cell has a cell wall, large central vacuole, and chloroplasts. Plant and animal cells are BOTH eukaryotes!!!

What does the Eukaryotic Cell have that Prokaryotic Cells does not? Prokaryotic Eukaryotic No nucleusHas a nucleus No membrane bound organelles Circular DNA Has membrane bound organelles

Cell Organelles © J Beauchemin 2006

Cell Organelles Organelle= “little organ” Found only inside eukaryotic cells Everything in a cell except the organelles is cytoplasm.

Cytoplasm Gel-like mixture Surrounded by cell membrane Contains hereditary material

Cell Membrane Boundary of the cell All cells have a cell membrane It separates the cells contents from its environment Controls movement of materials into and out of the cell.

Nucleus Control center of the cell Contains DNA Surrounded by a double membrane Usually the easiest organelle to see under a microscope Usually one per cell

Nucleolus Inside nucleus Contains RNA to build proteins

Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics

Cell Wall Found in plant and bacterial cells Rigid, protective barrier Located outside of the cell membrane Made of cellulose (fiber)

Cytoskeleton Acts as skeleton and muscle Provides shape and structure Helps move organelles around the cell Made of a web of proteins

Endoplasmic Reticulum A.k.a. “ER” Connected to nuclear membrane Highway of the cell Rough ER: studded with ribosomes; it makes proteins Smooth ER: no ribosomes; it makes lipids

Ribosome Site of protein synthesis Found attached to rough ER or floating free in cytoplasm. Produced in a part of the nucleus called the nucleolus (inner part of nucleus)

Golgi Complex- -Is responsible for sorting and correctly shipping the proteins produced in the ER. -Just like our postal packages which should have a correct shipping address, the proteins produced in the ER should be correctly sent to their respective address. -In the cell, shipping and sorting is done by the Golgi complex. It is a very important step in protein synthesis.

-This term literally means "small vessel". -This organelle helps store and transport products produced by the cell. -The vesicles are the transport and delivery vehicles like our mail and Federal Express trucks. Vesicles

Lysosomes Garbage disposal of the cell Contain digestive enzymes that break down old cell organelles and wastes

Mitochondria “Powerhouse of the cell” Cellular respiration occurs here to release energy for the cell to use Bound by a double membrane

Chloroplast Found only in plant cells Contains the green pigment chlorophyll Site of food (glucose) production- PHOTOSYNTHESIS Bound by a double membrane

Vacuoles Large central vacuole usually in plant cells Many smaller vacuoles in animal cells Storage container for water, food, enzymes, wastes, pigments, etc.

Centriole Aids in cell division

Quick Review Which organelle is the control center of the cell? Nucleus Which organelle holds the cell together? Cell membrane Which organelles are not found in animal cells? Cell wall, central vacuole, chloroplasts Which organelle helps plant cells make food? Chloroplasts What does E.R. stand for? Endoplasmic reticulum