The Cell

All organisms are made of cells, the organism’s basic

unit of structure and function.

Size range of cells

The Nucleus

Nucleus—control center-enclosed by nuclear envelope-contains most of the genes that control the entire cell-DNA organized with proteins into chromatin-nucleolus-producesribosomes

Mitochondria –powerhouse

•energy transformers of cells- producesATP- energy for cell + double membranes + contain ribosomes/DNA

Mitochondrial DNA is only passed on by mom

Ribosomes Construction Crew- make proteins-free- float in cytoplasm-bound- attachedto endoplasmicreticulum

Vacuoles

* Cell Closetfunction in cell maintenance & storage + food vacuole + contractile vacuole- removes excesswater + central vacuole (pictured)- in PLANTSStores water & maintains cell shape

Endoplasmic reticulumEndoplasmic reticulum- Intercellular highway

•Transport cell materials • two distinct regions+ rough ER (ribosomes attached)

- manufacture proteins for secretion - membrane production

+ smooth ER- synthesis of lipids- carbohydrate metabolism- detoxify drugs/poisons- stores calcium ions

Golgi Apparatus

* Packaging & shipping• finishes, sorts, and ships cell products• two poles + cis face + trans face

Enzymes in the Golgi modify products of the ER in stagesas they move through the Golgi stack from cis to trans face.

Lysosomes- clean up crewcontain hydrolytic enzymes- Primarily animal cells• digestive compartments + intracellular digestion + recycle cell material + program cell destruction (apoptosis)

Apoptosis – programmed cell death

http://www.hhmi.org/biointeractive/disease/ctl_video.html

The Cytoskeleton

Cytoskeleton•provides structural support for motility and regulation + network of fibers- microtubules- thick &

Hollow (straw) - microfilaments- thin &

Solid (toothpick)- intermediate filaments-

Medium & solid

Cilia & Flagella

-Cilia- short, hairlike, numerous. Cover entire cell-Flagella- long, only 1 or 2 on a cell

* Both function in movement* Found on outside of ANIMAL cells* Composed of microtubules (cytoskeleton)

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Centrosomes

• Found in animals primarily

• Produce microtubules during cell reproduction

• Animal cells contain centrioles whichcontain 9 sets of 3microtubules

Cell Membrane

Plasma Membrane- Bouncer•boundary that separates living cell fromits non-living surroundings + 8 nm thick + selectively permeable + unique structure relates to function

+ phospholipid bilayer

Cell Wall

Cell Walls (1° & 2°)Plant cells only*- Brick wall

•cellulose fibers•Middle lamella Made of pectin (sticky polysaccharide)

Cytoplasm/Cytosol--cytosol--Gelatinous fluid that surrounds organelles & holds cellular components (Na+, K+, amino acids, etc)

Cytoplasm-everything inCell EXCEPT nucleus

Chloroplasts- site of photosynthesis - Production crew-

* Only in PLANT cells* Made of thylakoid stacks

(grana) where reactions occur* green in color due to

chlorophyll

Peroxisome

Break down large, branchedFatty acid chains•+ contain specialized teams of enzymes - peroxide-producing oxidases and catalase

Leucoplast

* Basement/CellarNon-pigmented plastidsBulk storage of starch, commonly in roots

Chromoplast

* Crayons * * Responsible for pigment synthesis and storage*Commonly found in fruit, flowers, & aging leaves* assist chloroplasts in absorbing suns energy

The Endomembrane SystemIncludes:•nuclear envelope

•Endoplasmic reticulum

•Golgi apparatus

•Lysosomes

•Vacuoles

•Plasma membrane*

The organelles of the endomembrane system are related through direct contact or by the transfer of membrane segments as vesicles.

Endomembrane System Summary

Animal vs. Plant Cell

Unique to Plant Cells:- cell wall- large central vacuole- Plastids

Unique to Animal Cells:-Centrioles-Lysosomes- flagella and/or cilia

A Panoramic View of the Cell

Prokaryotic Eukaryotic+only in bacteria/archaebacteria Protists, Fungi, Plantae, Animalia

+no true nucleus/nuclear envelope true membrane-bound nucleus

+genetic material in nucleoid region genetic material in nucleus

+little to no organelles many organelles