Cell Organelles

Cell OrganellesOrganelle= “little organ”

Found only inside eukaryotic cells

Cell MembraneBoundary of the cellMade of a phospholipid bilayerContains proteins, steroids and carbohydrates on outside layerControls movement in and out of cellProtects cell from outside environmentSelective Permeability

CytoskeletonActs as skeleton and muscle

Provides shape and structure

Helps move organelles around the cell

Made of three types of filaments

CytoplasmContains cytosol

-water

- salts

- organic monomers and polymers

Contains organelles (including cytoskeleton)

Nucleus is separate from cytoplasm

The cytosol takes molecules and breaks them down, so that the individual organelles can use them

NucleusControl center of the cell

Contains DNA

Surrounded by a double membrane

Usually the easiest organelle to see under a microscope

Usually one per cell

Chromosomes and Chromatin

The Nuclear DNA of a cell is organized into chromosomes.Each chromosome is a single DNA molecule

The DNA is coated and organized with a wide variety of proteins. Collectively, the DNA and protein assembled chromosomes are referred to as chromatin

RibosomeSite 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?

Endoplasmic Reticulum

A.k.a. “ER”(membrane tubes and sacs)

Connected to nuclear membrane

Moves molecules from one area of cell to another

Rough ER: studded with ribosomes; it makes proteins and phospholipids

Smooth ER: no ribosomes; it makes lipids, produces hormones

Golgi ApparatusLooks like a stack of platesStores, modifies and packages proteinsMolecules transported to and from the Golgi by means of vesiclesVesicles given a label and transported to parts of the cellReceiving near ER, shipping gives rise to new vesicles

LysosomesGarbage disposal of the cellContain digestive enzymes that break down wastesBreak down worn out cell parts, substances taken into the cell, and bacteria During endocytosis it fuses with a vesicle (release contents outside of cell) Which organelles do

lysosomes work with?

Mitochondria“Powerhouse of the cell”Cellular respiration occurs here to release energy for the cell to useBound by a double membraneHas its own strand of DNA

VacuolesLarge central vacuole usually in plant cellsMany smaller vacuoles in animal cellsStorage container for water, food, enzymes, wastes, pigments, etc.Dispose of excess water What type of microscope may have

been used to take this picture?

Centriole

Aids in cell divisionFound only in animal cellsMade of short cylinders of microtubules

ChloroplastFound only in plant cells

Contains the green pigment chlorophyll

Site of food (glucose) production

Bound by a double membrane

Cell WallFound in plant and bacterial cellsRigid, protective barrier. Maintains turgor pressureLocated outside of the cell membraneMade of cellulose (fiber)

Quick ReviewWhich 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