Transcript micro intro organelles

Microscopes
Field of View
Fly’s Foot
Surface of an Erasable
Programmable Read-Only Memory
Silicon microchip
Eyelash hairs growing from the
surface of human skin
The surface of a strawberry
Bacteria on the surface of a human
tongue
Human sperm (spermatozoa)
Nylon hooks and loops of Velcro
Household dust: includes long hairs of cat fur, twisted
synthetic and woolen fibers,
serrated insect scales, a pollen grain, and plant and
insect remains
The weave of nylon stocking fibers
The head of a mosquito
Head louse clinging to a human
hair
Eight eyes (two groups of four) on
the head of a tarantula
Cut human hairs and shaving foam
between two razor blades
Cigarette paper the tobacco is
rolled in
Corroded surface of a rusty nail
Mushrooms spores
Clutch of butterfly eggs on a
raspberry plant
Calcium phosphate crystal
Spider Skin
Starch in a corn kernel
Intestinal Bacteria
Paramecium
Volvox
Hooke
Prokaryotes
Link to Cell Size
Eukaryotes
Fluid
Moasic
Model
http://multimedia.mcb.harvard.edu/anim_innerlife.html
Nucleus
Nucleus
• Contains the genes that control the cell;
localizing the cell’s DNA
• Nuclear envelope
- separates the nucleus contents from
cytoplasm
- double membrane with pores to regulate
what enters and exits nucleus
Nucleus
• Nucleolus – densely packed RNA and
proteins that makes up ribosomes
• Chromatin: threads of DNA that makes up
the chromosomes and their associated
proteins (histones)
Endomembrane System
• Membranes physically touch one another
or transfer membrane segments through
tiny vessicles
• Includes:
- Nuclear envelope
- Endoplasmic reticulum
- Golgi apparatus
- Lysosomes
- Peroxisomes
- Cell membrane
ER +
Ribosomes
Endoplasmic Reticulum
• Membranous labryinth extending from the
nuclear membrane
• Made of tubes and sacs called cisternae
Rough ER: ribosomes stud the
cytoplasmic surface
• Many types of specialized cells secrete
proteins made by the rough ER which are
moved in transport vesicles
• As the polypeptide chain grows from the
ribosomes, it goes into the ERs cisternal
space and folds into higher levels
• Some proteins (glycoproteins) are
covalently bonded to carbohydrates or are
embedded in newly synthesized lipid
membranes
Smooth ER: cytoplasmic surface
lacks ribosomes
• Function:
- synthesis of phospholipids and steroids
-carbohydrate metabolism,
-detoxification of drugs/poisons
Ribosomes
• Sites where cells assemble proteins
according to genetic instructions
• Free ribosomes are suspended in the
cytoplasm which make proteins that will
function in the cytosol
• Bound ribosomes are attached to the
endoplasmic reticulum which make
proteins that be included in membranes or
transported outside the cell
Golgi Bodies
Golgi Apparatus
• Flattened, inner-connected membranous
sacks with cisternae
• Products of ER are modified, stored, and
shipped via transport vesicles
• Secretory vesicles have “docking sites”
that recognize the surface of specific
organelles
Lysosome
• Membrane-enclosed bag of hydrolytic
enzymes that digests macromolecules
• Works best in an environment with pH = 5
• Amoeba eat via phagocytosis = engulf
food then digest as the lysosome fuses to
it
• Usually only found in animals
Lysosome
Animation: Lysosomes
Peroxisome
Peroxisome
• Contains enzymes that transfer hydrogen
from various substrates to oxygen,
producing H2O2
• The H2O2 is then converted into water
• Helps breakdown fats to be used in
mitochondria for energy
• Detoxify alcohol in the liver
Mitochondria
Mitochondria
• Site of cellular respiration which generates
ATP from sugars and fats
• Have ribosomes and small amounts of
DNA for its own protein synthesis
• 100s-1000s per cell which correlate to the
metabolic activity of the cell
• Enclosed in phospholipid bi-layer with
inner foldings called cristae
Chloroplasts
Chloroplasts
• Convert solar energy into chemical energy
by absorbing sunlight and using it to
synthesize glucose from CO2 and H2O.
• Plastids: specialized organelles in plants
- Leucoplasts: store starch in roots and
tubers
- Chromoplasts: enriched in pigments that
give plants their colors
- Chloroplasts: contain the green pigment
cholorphyll
• What
organelle is
taking up
most of the
space in this
plant cell?
Vacuole
• Central vacuole: stores water, organic
compounds, ions, wastes, and hydrolytic
enzymes
• Tonoplast: membrane surrounding plant
vacuole
• Vacuoles and vesicles are both
membranous sacs, but vacuoles are larger
Cytoskeleton
Cytoskeleton
• Network of fibers that allow for material
movement within the cell
• microtubules – larger filaments that help
• move organelles during cell division
• form hair-like extensions on cell surface for
movement (cilia or flagella)
• Centrioles – rings of microtubules which form
spindle fibers to aide in cell division
• Microfilaments (actin) – smaller filaments
that maintain shape and aid in muscle
contraction
Centriole
Flagella
Cell Wall
• Made of cellulose (polysaccharide) not
digested by most animals
• Rigid structure that supports and protects
plant cell by preventing the excess uptake
of water
- turgor pressure from vacuole assists in
support
• Allows movement of materials in/out of cell
through plasmodesmata (channels)
Cytoplasm
Harvard Cell Animation/
• Cytosol: semi-fluid medium in which organelles are
suspended
• Mostly water but also contains ions, sugars, amino acids,
RNA, and ATP (cell energy)
Plasmolyzed
Flaccid
Turgid
Animation of Endo/Exocytosis
Exocytosis