Transcript HGSS Chapter 2: The Cell

Cell Wall
Endoplasmic
Reticulum
Ribosomes
Cytoplasm
Chromosomes
Nucleus
Mitochondria
Schematic of the plasma membrane
http://www.ncnr.nist.gov/programs/reflect/rp/biology/cell_membrane.html
Cell Division:
1) Mitosis-ordinary cell division
2) Meiosis-gamete cell division
Mitosis:
Ordinary cell division
Mitosis:
I. Chromosomes are expanded into long
structures in the nucleus and are invisible
under the light microscope.
Mitosis:
II. Chromosomes replicate and condense. With
appropriate staining, they can now be seen
under a microscope.
Mitosis:
III. The nuclear wall degrades, spindles form
and attach themselves to the chromosomes.
Mitosis:
IV. Spindles pull the chromosome pairs apart,
pulling them to opposite poles of the cell.
Mitosis:
V. Nucleus develops around each set of
chromosomes and the cell wall starts to form,
splitting the cell.
Mitosis:
VI. Nucleus and cell wall complete development
and chromosomes expand, giving two daughter cells.
Meiosis:
Cell Division
Generating Gametes
Meiosis:
I. As in mitosis, chromosomes
replicate and condense.
Meiosis:
II. Unlike mitosis, the maternal (solid) and
paternal (dotted) chromosomes pair up
and exchange genetic material.
Meiosis:
III. Spindles form, attach themselves and
pull the chromosomes to the poles of the cell.
Meiosis:
IV. The cell divides.
Meiosis:
V. Spindles form again and pull each
chromosome away from its partner.
Meiosis:
VI. Each cell divides again, reducing the number of
chromosomes to half that of the original cell.
Cell Workings:
Metabolism &
Catabolism
Key Concepts:
1) Lock & Key
2) Cut or Paste
1. Substrate and enzyme
substrate
2. bind together, forming a
substrate-enzyme complex.
enzyme
3. A chemical reaction occurs,
4. leaving a product when the
enzyme dissociates.
product
Tyrosine
tyrosine
hydroxylase
DOPA
(dihydroxyphenylalanine)
DOPA
decarboxylase
DA
(dopamine)
dopamine
b hydroxylase
NE
(norepinepherine)
Cell Communication:
Key Concepts:
1) Lock (Receptor) & Key (Hormones,
Neurotransmitters)
2) Dimmer Switch
The Neuron
Terminal
Dendrites
Cell
Body
Axon
Nucleus
Buttons
Glial Cell
Neurons
© DennisKunkel: www.DennisKunkel.com
Neurons
http://www.alz.org/brain/05.asp
Synaptic Button
Vesicle
Neurotransmitter
molecules
Receptor
Vesicle
1. Neuron fires.
2. Vesicles release
neurotransmitter which
exits the cell.
Neurotransmitter
3. Neurotransmitter
binds with receptor
initiating a cascade
of chemical events
in the next cell.
Presynaptic
Neuron
Enzyme
Presynaptic
Receptor
4. Excess neurotransmitter chewed up by enzymes
and/or taken back by the neuron
where it may also be degraded
Enzyme
by enzymes.
Postsynaptic
Receptor
Postsynaptic
Neuron
http://www.drugabuse.gov/pubs/teaching/teaching4/largegifs/slide10.gif
http://www.driesen.com/neurotransmitter_processes.jpg
Effects of
neurotransmission:
1) Short term = ion transfer
(changes polarity of postsynaptic neuron)
2) Long term = second messenger system
(changes proteins, changes dimmer switch)
Ions
Neurotransmitter
Receptor
Enzyme
Activating
Ion Channel
Ion Channel
Ions
Neurotransmitter
Receptor
Scaffolding
Molecule
Ion Channel
Second Messenger Molecule
Signal to Cell
Serotonin projections from the Raphe
Raphe nuclei
http://learn.genetics.utah.edu/content/addiction/reward/pathways.html
Serotonin second
messenger signaling
pathway
http://www.ariadnegenomics.com/products/pathway-studio/sample-pathways/serotoninr-1/