Cell Organelles J Beauchemin 2006 Cell Organelles Organelle

Cell Organelles © J Beauchemin 2006

Cell Organelles Organelle= “little organ” Found only inside eukaryotic cells All the stuff in between the organelles is cytosol Everything in a cell except the nucleus is cytoplasm

Cell Membrane Boundary of the cell Made of a phospholipid bilayer

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

Cytoskeleton Acts as skeleton and muscle Provides shape and structure Helps move organelles around the cell Made of three types of filaments

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 cytosol Produced in a part of the nucleus called the nucleolus That looks familiar…what is a polypeptide?

Golgi Apparatus Looks like a stack of plates Stores, modifies and packages proteins Molecules transported to and from the Golgi by means of vesicles

Lysosomes Garbage disposal of the cell Contain digestive enzymes that break down wastes Which organelles do lysosomes work with?

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

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

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

Vacuoles Large central vacuole usually in plant cells Many smaller vacuoles in animal cells Storage container for water, food, enzymes, wastes, pigments, etc. What type of microscope may have been used to take this picture?

Centriole Aids in cell division Usually found only in animal cells Made of microtubules Where else have we talked about microtubules?

Cells need workers = proteins! Making proteins n to run daily life & growth, the cell must… read genes (DNA) build proteins n n structural proteins (muscle fibers, hair, skin, claws) enzymes (speed up chemical reactions) signals (hormones) & receptors organelles that do this work… nucleus ribosomes endoplasmic reticulum (ER) Golgi apparatus

Proteins do all the work! one of the major job of cells is to make proteins, because… proteins do all the work! structural enzymes signals receptors DNA proteins cells

Nucleus Function n n control center of cell protects DNA instructions for building proteins Structure n n nuclear membrane nucleolus ribosome factory n chromosomes DNA

cytoplasm jelly-like material holding organelles in place vacuole & vesicles transport inside cells storage lysosome food digestion garbage disposal & recycling nucleolus produces ribosomes nucleus protects DNA controls cell chromosomes DNA mitochondria make ATP energy from sugar + O 2 cell membrane cell boundary controls movement of materials in & out recognizes signals

Ribosomes Function n n protein factories read instructions to build proteins from DNA Structure n n some free in cytoplasm some attached to ER Ribosomes on ER

cytoplasm jelly-like material holding organelles in place vacuole & vesicles transport inside cells storage mitochondria make ATP energy from sugar + O 2 cell membrane cell boundary controls movement of materials in & out recognizes signals lysosome food digestion garbage disposal & recycling nucleolus produces ribosomes nucleus protects DNA controls cell ribosomes build proteins

Endoplasmic Reticulum Function n works on proteins helps complete the proteins after ribosome builds them n makes membranes Structure n rough ER ribosomes attached works on proteins n smooth ER makes membranes

cytoplasm jelly-like material holding organelles in place vacuole & vesicles transport inside cells storage lysosome food digestion garbage disposal & recycling ribosomes builds proteins mitochondria make ATP energy from sugar + O 2 cell membrane cell boundary controls movement of materials in & out recognizes signals nucleus protects DNA controls cell ER works on proteins makes membranes

Golgi Apparatus Function n finishes, sorts, labels & ships proteins like UPS headquarters n n shipping & receiving department ships proteins in vesicles “UPS trucks” vesicles carrying proteins Structure n membrane sacs transport vesicles

cytoplasm jelly-like material holding organelles in place vacuole & vesicles transport inside cells storage lysosome food digestion garbage disposal & recycling ribosomes builds proteins mitochondria make ATP energy from sugar + O 2 cell membrane cell boundary controls movement of materials in & out recognizes signals nucleus protects DNA controls cell ER helps finish proteins makes membranes Golgi apparatus finishes, packages & ships proteins

endoplasmic reticulum nucleus protein on its way! DNA RNA vesicle TO: vesicle ribosomes TO: finished protein Making Proteins Golgi apparatus

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