cell organelles and function · cell membrane proteins float around within the membrane or on its...
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Cell Organelles and Function
Objectives
describe the structure and function of cell organelles
compare and contrast structures of plant and animal cells
Recallmicroscopes provide the ability to study cells
allowed biologists to increase their understanding of the structure and function of cells and cell organelles
RecallThere are two types of cells
prokaryotic and eukaryotic - these differ in size and complexity
Organelle
a specialized structure within a cell with a specific function
examples: nucleus, chloroplast
organelles are the functioning parts of the cell, they work together to allow the cell to perform life processes
some organelles are enclosed in their own membrane - others are not
https://www.youtube.com/watch?v=Fzj6TRnXmps&feature=related
The Nucleusthe mayor of city hall
the nucleus houses the majority of genetic material of a cell
the “brain” of the cell
controls all activity within the cell
uses DNA as a blueprint (similar to a city or building) to direct the production of protein
The Nucleuscontains a eukaryotic cell’s genetic library
The Nucleusnucleolus - the densest area within the nucleus; the location for production of ribosomes
chromatin - stringy material made of proteins and DNA that makes up the majority of the nucleus
chromatin is composed of DNA and protein, just before the cell divides it condenses into chromosomes
note: chromosomes float inside of the nucleus around the nucleolus, they are not found in the nucleolus
Chromosomes
hereditary material within the nucleus
made up of coiled DNA and proteins
carry the genetic code
each species has a characteristic number of chromosomes - humans have 46
Ribosomescarry out manual labour in the form of protein synthesis for the nucleus (factories)
bring together all the raw ingredients such as RNA (copies of the original DNA blueprints) and amino acids to assemble proteins
the proteins created are essential to cell and organismal function
they can be attached to the ER or free-floating in the cytoplasm
Ribosomes and Protein
think of proteins as machinery for cell function, similar to electricity and plumbing in a real city
the nucleolus is a non-membrane bound structure in the nucleus
it is composed of proteins and nucleic acids found within the nucleus
these proteins (rRNA) form future ribosomes
The Endoplasmic Reticulum
two types of ER - smooth ER and rough ER
this extensive network makes up approximately half of all membranous tissue of the cell and is the site of membrane and protein synthesis
the ER system is much like a road system along which industry can be found - twisting network of canals and sacs that connects the cell membrane to the nuclear membrane
goods are manufactured and shipped to needed areas via the ER “road systems”
Rough ER is named for the presence of ribosomes along its membrane and is the source of protein
Smooth ER lacks ribosomes and is responsible for lipid synthesis and processes a variety of metabolic principles such as drug detoxification
The Endoplasmic Reticulum
Golgi Apparatusalso known as the golgi body or the golgi complex
processes and packages macromolecules such as proteins and lipids
particularly important in the processing of proteins for secretion
forms a part of the cellular endomembrane system
the golgi body produces vesicles
The Endomembrane System
the ER manufactures membranes and performs many other biosynthetic functions
the golgi apparatus finishes, sorts, and ships cell products
Lysosomesdigestive sacs that can break down macromolecules in the cell and various structures as needed
digestion is carried out with lysosomal enzymes
similar to waste disposal in cities, lysosomes keep excessive or bulky macromolecules from building up in the cell
found only in animal cells
http://highered.mheducation.com/sites/0072943696/student_view0/chapter3/animation__lysosomes.html
Vesiclesmembrane packages composed of a lipid bilayer
four main types of vesicles:
vacuoles
lysosomes
transport vesicles
secretory vesicles
Vacuolesmembrane bound sacs or spaces containing water or other materials
food vacuoles are digestive organelles they become waste vacuoles once digested
contractile vacuoles maintain water balance - plant cells
plant cells have a central vacuole that is important in maintaining plant turgidity
Plants vs. Animal Cells
mitochondria in red
nucleus in peach ER in blue
mitochondria in red
nucleus in green plastids in yellow
Plant vs Animal Cells
we can identify three organelles unique to plant cells:
cell wall (versus the cell membrane in animal cells)
central vacuole (regular vacuoles are found in animal cells
chloroplasts (animals do not perform photosynthesis - this is what makes plants autotrophs and animals heterotrophs)
https://www.youtube.com/watch?v=uohe2V4yOzE&feature=BFa&list=PLC29EC4BD3F282504
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Plant Cell 1. nuclear pore 2. chromatin 3. nucleolus 4. nuclear membrane 5. ribosomes 6. ER 7. vesicles 8. cell membrane 9. & 12. cell wall 10. cytoplasm 11. golgi body 13. mitochondria 14. & 15. microtubule 16. chloroplast 17. vacuole
Energy Transduction Organelles
mitochondria and chloroplasts are the main energy transformers of the cell
Energy Transduction Organelles
mitochondria carry out the processes of cellular respiration
they make chemical energy for the cell known as ATP from oxygen
chloroplasts carry out the processes of photosynthesis (process of converting light into chemical energy)
pigment (chlorophyll)
Cytoskeletonprovides structural support to the cell, the cytoskeleton also functions in cell mobility and regulation
microtubules - compression support
microfilaments - tension support
centrosomes and centrioles
used in animal cell division
cilia (microvilli) and flagella in prokaryotes
Cell Surface and Junctions
plant cells are encased by cell walls
they also have a cell membrane beneath the cell wall
membranes are a characteristic of all cells
Cell Membrane (Plasma)
animal cells have these
separates the interior of all cells from the outside environment
serves as protection and keeps cell contents together
selectively permeable - controls what comes in and out
made up of fats, lipids, and proteins
https://www.youtube.com/watch?v=qBCVVszQQNs
phospholipid - composted of a phosphate and
fatty acid
hydrophilic head is “water loving” or soluble in water
and the hydrophobic tail is “water hating” or insoluble in water
Cell Membraneproteins float around within the membrane or on its surface
functions:
structural support
surface binding sites for molecules like hormones
recognition sites for cell to cell communication and interaction
transport molecules across the membrane
also contains cholesterol - keeps phospholipids stable and helps retain the membranes shape
Additional Resources
•Cell Grand Tour: www.youtube.com/watch?v=8IlzKri08kk
•Tour of the Cellhttp://www.youtube.com/watch?v=1Z9pqST72is
• Bio-Coach activity: Self-quiz with answers http://www.phschool.com/science/biology_place/biocoach/cells/quiz.html?x=150&y=15
• Biology: Cell structureshttps://www.youtube.com/watch?v=URUJD5NEXC8