By the end of today: Name a function of each organelle
Jan 05, 2016
By the end of today: Name a function of each organelle
The nucleusContains genetic
informationHas a double
membrane with pore complexes
Contains nucleolus – a structure where rRNA is synthesized
Fun fact: your red blood cells do not have nucleii (anucleated)
Endoplasmic reticulumSmooth ER
Synthesis of lipids, metabolism of carbohydrates and detoxification of drugs and poisons
Fun fact – cells that synthesize hormones (steroids which are lipids) , such as testes and ovaries are rich in smooth ER
Another fun fact - Also proliferation of smooth ER in response to drugs and alcohol
Rough ERProteins are
synthesized using ribosomes and then in the rough ER they are folded and carbohydrates are added to make a glycoprotein
The membrane buds off to form a transport vesicle which takes the protein to another area in the cell
GolgiProducts of the ER are
modified, stored and sent to other destinations in the golgi
Golgi can also manufacture macromolecules, such as polysaccharides
StrucutreTrans face – shipping sideCis face – near the rough
ERFun fact – molecular
identification tags are added to golgi products that aid in their placement within the cell
Lysosomes – Digests macromolecules using enzymesPhagocytosis – Eating or digestion of products
Autophagy – Breaks down damaged organelles
Lysosomal lipase is missing
Vacuoles Different functions in
different cellsEx. Food vacuoles,
contractile vacuoles (pump excess water out of the cell), and in plant cells central vacuole
Plant cells central vacuole has many functions such as organic compound reserve, disposal site, pigment storage, poison storage, etc.
MitochondriaThe site of cellular
respiration (creates energy from food)
Has two membranesHas DNAFun fact – there are
lots of mitochondria in your muscle cells and you can increase the amount with exercise
ChloroplastsThe site of photosynthesisCreates organic molecules that can be
broken down in the mitochondriaThey are not found in animal cells
CytoskeletonFunction
SupportMotility Regulation
TypesMicrotubulesMicrofilamentsIntermediate
Filaments
MicrotubulesStructure
Hollow rods constructed from tubulin dimers (protein with two subunits)
FunctionAid in shape, support
and form tracks which organelles move along
Examples : Centrosomes and cilia and flagella
How a cilia or flagellum worksD:\Chapter_06\
C_Animation_and_Video_Files\06_Animations\06_24CiliaFlagella_A.swf
MicrofilamentsStructure
Solid rods built from twisted actin chains (smallest)
FunctionBears tension
helps support the cell’s shape
Movement Contraction of muscle
cells Amoeboid movement
Microfilaments – muscle contraction
Microfilaments – amoeboid movement
Amoeba moving
Structure Proteins coiled into
thicker cablesBigger than
microfilaments but smaller than microtubules
Function Tension bearing
Permanent fixtures of cells (do not move)
Intermediate Filaments
Check for understandingCell parts checklist
Contrast cell types As you are doing the worksheet, review the
function of each organelle with your group
DiffusionThe movement of molecules from an area of
higher concentration to an area of lower concentration
What determines whether a substance will enter or leave a cell?
Diffusion LabWill substances move through the
membrane?What determines which substances will
move?
Check for understandingDefine diffusionWhat types of molecules could move freely
through a cell membrane?
Demo with potatoe
MembranesKnow the parts of the cell membrane and
what the function is
MembranesFunction
Acts as a barrier that separates the inside and outside of the cell
Regulates the “traffic” of molecules into and out of the cell
MembranesStructure
Lipids and proteinsAmphipathic
(hydrophilic and hydrophobic regions)
Fluid mosaic model
For the following that are circled: Give the name and at least three facts, including the function
Two types of movement through the membranePassive transport – Does not need energy to transport
Active transport – Uses energy to transport
Something to ponder…Most fish are not able to move between salt
water and fresh water. Why do you think this is?
Osmosis labBe able to define osmosisDetermine which way water will move given
certain solute concentrations
OsmosisThe diffusion of water
across a selectively permeable membrane.Ex. Lettuce and salad
dressingOr wilted lettuce in
water
Water balance in cells
Check for understandingDraw a representation of the concept of
osmosis. (Hint: You may want to draw solutes to one side of a membrane and show which way the water is moving)
Water PotentialRead exercise 1C in lab notebook
Water potential is the potential for water to do work, or move out of the cellΨ = Ψp + ΨsWater potential equals the pressure potential plus the
solute potential.Increasing the pressure increases water potential (+)Increasing solutes decreases water potential (-)
Check for understandingIf a plant cell has a lower water potential
than its surrounding environment and if pressure is equal to zero, is the cell hypertonic (in terms of solute concentration) or hypotonic to its environment? Will the cell gain water or lose water?