The Cell and Cell Transport

Anatomy and Physiology

The Cell and Cell Transport

• Functional anatomy – study of structures as they relate to function

• We study a typical cell (composite cell)

• Cell size – range from 7.5 µm to 150 µm– µm = 1 millionth of a meter; 1 x 10-6 meters

Nerve Cells• Features

– Surface is sensitive to stimuli

– Has long extensions

• Functions– Detects changes in

environment– Transmits nerve

impulses throughout body http://www.becomehealthynow.com/images/

organs/nervous/nerve_cell_bh.jpg

Muscle Cells• Features

– Elongated, threadlike– Contain tiny fibers that

slide together

• Functions– Contract to allow

movement of body parts

http://missinglink.ucsf.edu/lm/IDS_101_histo_resource/images/351Blabeled_copy.jpg

Red Blood Cells• Features

– Contains hemoglobin (attract and releases O2)

• Functions– Transports O2 in the

bloodstream

http://www.odec.ca/projects/2007/nand7t2/images/rbc.jpg

Gland Cells• Features

– Contain sacs that release secretions to the outside of the cell

• Functions– Release hormones,

enzymes, mucus, and sweat

http://mwsu-bio101.ning.com/forum/topics/distinct-human-celltypes-1

Immune Cells

• Features– Some can engulf other

cells– Some manufacture

antibodies– Some can destroy

other cells

• Functions– Recognize and destroy

“nonself” cells (cancer, bacteria) http://www.jyi.org/articleimages/821/originals/

img0.jpg

Membrane bound organelles

• Plasma membrane• Endoplasmic Reticulum• Golgi apparatus • Lysosomes• Peroxisomes • Mitochondria • Nucleus

Non membrane bound organelles

• Ribosomes

• Cytoskeleton

• Cilia and flagella

• Nucleolus

Plasma Membrane• Cell boundary; protein molecules serve as

markers that identify cell’s purpose

http://micro.magnet.fsu.edu/cells/plasmamembrane/images/plasmamembranefigure1.jpg

Endoplasmic Reticulum• Rough ER –

ribosomes attached synthesize proteins that leave via Golgi apparatus

• Smooth ER – synthesizes lipids in cell membranes, steroid horomones, and certain CHO

http://www.sciencegateway.org/resources/biologytext/cb/org/smooth_er-em.gif

http://www.sciencegateway.org/resources/biologytext/cb/org/rough_er-em.gif

Golgi apparatus

• Synthsize CHO, combines it with a protein, & packages the product as globules of glycoprotein (proteins that contain oligosaccharide chains (glycan) covalently attached to polypeptide side-chains)

http://www.beyondbooks.com/lif71/images/00016960.jpg

Lysosomes• Digestive enzymes that break down worn

cell parts and ingested particles

http://www.cartage.org.lb/en/themes/sciences/zoology/animalphysiology/anatomy/animalcellstructure/Lysosomes/lysosome.jpg

Peroxisomes• Contain enzymes that detoxify harmful

substances

http://micro.magnet.fsu.edu/cells/peroxisomes/images/peroxisomesfigure2.jpg

Mitochondria• Catabolism (the set of pathways that break

down molecules into smaller units and release energy); ATP synthesis

http://microbewiki.kenyon.edu/images/thumb/2/25/Mitochondria.gif/400px-Mitochondria.gif

Nucleus

• Genetic code which dictates protein synthesis

http://www.frontiers-in-genetics.org/en/pictures/nucleus_1.jpg

Ribosomes

• Site of protein synthesis

http://www.cbv.ns.ca/bec/science/cell/page11a.gif

Cytoskeleton• Framework to

support the cell and organelles; functions in cell movement; forms cell extensions

http://www.immediart.com/catalog/images/bigger_images/SPL_6_P780110-Fibroblast_cells_showing_cytoskeleton.jpg

Cilia and flagella• Hair like extensions

that serve to move substance over the cell or propel sperm cells

http://www.pcdfoundation.org/images/Johnny%27s%20cilia%20pic.jpg

http://digitaldaily.allthingsd.com/files/2008/01/sperm.jpg

Nucleolus

• Part of the nucleus; helps form ribosomes

http://www.palaeos.com/Invertebrates/Lists/Images/nucleolus.jpg

Fluid Mosaic Model

• The current model of the plasma or cell membrane that we use.

• It is a mosaic (made of many pieces)

• Fluid – molecules are able to float around like icebergs

http://micro.magnet.fsu.edu/cells/plasmamembrane/images/plasmamembranefigure1.jpg

• Hydrophillic = water lover

• Hydrophobic = afraid of water

Passive Transport

• Requires no chemical energy

• 4 types– Diffusion– Facilitated diffusion– Filtration– Osmosis

Diffusion• Movement of particles

from an area of higher concentration to an area of lower concentration

• http://www.toltecint.com/how_dialysis_works/diffusion.jpg

Facilitated diffusion• the spontaneous passage

of molecules or ions across a biological membrane passing through specific transmembrane transport proteins. The facilitated diffusion may occur either across biological membranes or through aqueous compartments of an organism

• http://www.williamsclass.com/SeventhScienceWork/ImagesCellBricks/facilitatedDiffusion.jpg

Filtration• movement of water and

solute molecules across the cell membrane due to hydrostatic pressure generated by the cardiovascular system. Filtration is a mechanical or physical operation which is used for the separation of solids from fluids

• http://upload.wikimedia.org/wikipedia/commons/thumb/8/86/Filtration_diagram.svg/238px-Filtration_diagram.svg.png

Osmosis• Osmotic Pressure – water potential of the

two solutions

• Hypertonic – higher salt concentration

• Isotonic – same salt concentration inside and out

• Hypotonic – lower salt concentration

Osmosis• movement of water

molecules across a partially-permeable membrane down a water potential gradient. More specifically, it is the movement of water across a partially permeable membrane from an area of high water potential (low solute concentration) to an area of low water potential (high solute concentration).

– http://en.wikipedia.org/wiki/Osmosis

• http://www.ndpteachers.org/perit/osmosis2.gif

Active Transport

• Movement against the concentration gradient (from low to high concentration)

–Active Transport

–Phagocytosis

–Pinocytosis

–Exocytosis

Active Transport• Please print up to this

point in the ppt. I will print copies of the additional slides for you!!!