Chemistry Comes Alive
Lab 2
Matter
• The “stuff” of the universe
• Anything that has mass and takes up
space
• States of matter
– Solid – has definite shape and volume
– Liquid – has definite volume, changeable
shape
– Gas – has changeable shape and volume
Energy
• The capacity to do work (put matter into
motion)
• Types of energy
– Kinetic – energy in action
– Potential – energy of position; stored
(inactive) energy
PLAY
Energy Concepts
Major Elements of the Human
Body
•
•
•
•
Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Lesser and Trace Elements of the
Human Body
• Lesser elements make up 3.9% of the
body and include:
– Calcium (Ca), phosphorus (P), potassium (K),
sulfur (S), sodium (Na), chlorine (Cl),
magnesium (Mg), iodine (I), and iron (Fe)
• Trace elements make up less than 0.01%
of the body
– They are required in minute amounts, and
are found as part of enzymes
Atomic Structure
• The nucleus consists of neutrons and
protons
– Neutrons – have no charge and a mass of one
atomic mass unit (amu)
– Protons – have a positive charge and a mass of
1 amu
• Electrons are found orbiting the nucleus
– Electrons – have a negative charge and 1/2000
the mass of a proton (0 amu)
Models of the Atom
• Planetary Model – electrons move around
the nucleus in fixed, circular orbits
• Orbital Model – regions around the nucleus
in which electrons are most likely to be found
(like a cloud)
Models of the Atom
Figure 2.1
Molecules and Compounds
• Molecule – two or more atoms held together
by chemical bonds
• Compound – two or more different kinds of
atoms chemically bonded together
Types of Chemical Bonds
• Ionic
• Covalent
• Hydrogen
Comparison of Ionic, Polar Covalent, and
Nonpolar Covalent Bonds
Figure 2.8
Formation of an Ionic Bond
Figure 2.5a
Single Covalent Bonds
Figure 2.6a
Cells: The Living Units
THE CELL
Cell Theory
• The cell is the basic structural and
functional unit of life (Schleiden & Schwann)
• Organismal activity depends on individual
and collective activity of cells
• Biochemical activities of cells are dictated by
subcellular structure
• Continuity of life has a cellular basis
• Virchow expanded on the cell theory and
concluded “one living cell could only originate
from another living cell”
Human cells are microscopic in
size , but they vary considerably
in size and differ even more in
shape. For example : flat, brick
shaped, threadlike, and irregular
shapes.
Composition of the CELL
• Plasma membrane
• Cytoplasma
• Organelles
• Nucleus
Part of the Cell
• Plasma membrane: surrounds the
entire cell, forming its outer
boundary
• Cytoplasma: living material inside
the cell (except the nucleus)
• Nucleus: this structure contains
the genetic code
Plasma membrane
• It is the membrane that encloses
the cytoplasm and form the outer
boundary of the cell.
• This membrane is compose by two
layers of phospolipids, also a fat
molecule called cholesterol (help to
stabilize) and proteins (as receptor)
Plasma Membrane
Figure 3.3
Functions of Membrane Proteins
• Transport
• Enzymatic activity
• Receptors for signal
transduction
Figure 3.4.1
Functions of Membrane Proteins
• Intercellular
adhesion
• Cell-cell
recognition
• Attachment to
cytoskeleton and
extracellular matrix
Figure 3.4.2
Passive Membrane Transport:
Diffusion
• Simple diffusion – nonpolar and lipidsoluble substances
– Diffuse directly through the lipid bilayer
– Diffuse through channel proteins
• Facilitated diffusion
– Transport of glucose, amino acids, and ions
– Transported substances bind carrier proteins
or pass through protein channels
Carriers
• Are integral transmembrane proteins
• Show specificity for certain polar molecules
including sugars and amino acids
Diffusion Through the Plasma
Membrane
Figure 3.7
Effect of Membrane Permeability on
Diffusion and Osmosis
Figure 3.8a
Effects of Solutions of Varying
Tonicity
• Isotonic – solutions with the same solute
concentration as that of the cytosol
• Hypertonic – solutions having greater solute
concentration than that of the cytosol
• Hypotonic – solutions having lesser solute
concentration than that of the cytosol
Active Transport
• Uses ATP to move solutes across a
membrane
• Requires carrier proteins
PLAY
Active Transport
Types of Active Transport
Figure 3.11
Cytoplasma
• It is the specialized living material of cells
• It lies between the plasma membrane and
the nucleus
• Numerous small structure (organelles) are
part of the cytoplasma, along with the fluid
that serves as the interior
environment of each cell
Cytoplasmic Organelles
• Specialized cellular compartments
• Membranous
– Mitochondria, lysosomes, endoplasmic
reticulum, and Golgi apparatus
• Nonmembranous
– Cytoskeleton, centrioles, and
ribosomes
Organelles
•
•
•
•
•
•
Ribosomes
Endoplasmic reticulum
Golgi apparatus
Mitocondria
Lysosomes
Centrioles
CELL PART
STRUCTURE
FUNCTION(S)
Plasma
Membrane
Phospholipid bilayer
studded with proteins
Serves as the boundary
of the cell. P and C
(outer surface) perform
various functions (Ex.
markers and receptor)
Ribosomes
Tiny particles each
made up of rRNA
subunits
Synthesize proteins; a
cell’s “protein factories”
Endoplasmic
Reticulum
(ER)
Membranous network
of interconnected
canals and sacs, some
with ribosome (rough
ER) and some without
(smooth ER)
Rough ER receives and
transports synthesized
proteins
Smooth ER synthesizes
lipids and carbohydrates
CELL PART
Golgi
apparatus
STRUCTURE
Stack of flattened,
membranous sacs
Mitochondria Membranous capsule
containing a large,
folded membrane
encrusted with
enzyme
Lysosomes
“Bubble” of enzymes
encased by membrane
FUNCTION(S)
Chemically processes,
then packages
substances from ER
ATP synthesis; a cell’s
“powerhouse”
A cell’s “digestive
system”
CELL PART
STRUCTURE
FUNCTION(S)
Nucleus
Doublemembraned,
spherical envelope
containing DNA
strands
Dictates protein
synthesis, thereby
playing and essential
role in other cell
activities, namely active
transport, metabolism,
growth and heredity
Nucleolus
Dense region of the Plays an essential role
nucleus
in the formation of
ribosomes
Mitochondria
Figure 3.17
Endoplasmic Reticulum (ER)
Figure 3.18a and c
Golgi Apparatus
Figure 3.20a
Nucleus
• Contains nuclear envelope, nucleoli,
chromatin, and distinct compartments rich in
specific protein sets
• Gene-containing control center of the cell
• Contains the genetic library with blueprints
for nearly all cellular proteins
• Dictates the kinds and amounts of proteins
to be synthesized
Nucleoli
• Dark-staining spherical bodies within the
nucleus
• Site of ribosome production
Nucleus
Figure 3.28a
Cell Cycle
• Interphase
– Growth (G1),
synthesis
(S), growth
(G2)
• Mitotic phase
– Mitosis and
cytokinesis
Figure 3.30
Mitosis
Cell Division
• Essential for body growth and tissue repair
• Mitosis – nuclear division
• Cytokinesis – division of the cytoplasm
Mitosis
• The phases of mitosis are:
– Prophase
– Metaphase
– Anaphase
– Telophase
Cytokinesis
• Cleavage furrow formed in late anaphase
by contractile ring
• Cytoplasm is pinched into two parts after
mitosis ends
Early and Late Prophase
• Asters are seen
as chromatin
condenses into
chromosomes
• Nucleoli
disappear
Early mitotic
spindle
Fragments
of nuclear
envelope
Pair of
centrioles
Polar
microtubules
Centromere
• Centriole pairs
separate and
the mitotic
spindle is
formed
Aster
Kinetochore
Chromosome, consisting
of two sister chromatids
Early prophase
Kinetochore
microtubule
Late prophase
Spindle
pole
Metaphase
• Chromosomes cluster
at the middle of the cell
with their centromeres
aligned at the exact
center, or equator, of
the cell
• This arrangement of
chromosomes along a
plane midway between
the poles is called the
metaphase plate
Metaphase plate
Spindle
Metaphase
Anaphase
• Centromeres of the
chromosomes split
• Motor proteins in
kinetochores pull
chromosomes
toward poles
Daughter chromosomes
Anaphase
Telophase and Cytokinesis
• New sets of
chromosomes extend
into chromatin
• New nuclear
membrane is formed
from the rough ER
Nucleolus
forming
• Nucleoli reappear
• Generally cytokinesis
completes cell division
Contractile
ring at
cleavage
furrow
Nuclear
envelope
forming
Telophase and cytokinesis
THE MICROSCOPE
PROCEDURES
• 1- Turn on the illuminator using the on/off switch
• 2- Turn the nosepiece to bring the 4X objective (scanner) into
position
• 3- Raise the stage into its highest position
• 4- Place a slide of the letter “e” in the slide clamp on the stage
• 5- Turn the coarse adjustment knob to bring the “e” into focus
• 6- Measure the field (the brightly lighted circle that you see
when you look through the ocular lens)
• 7- Center the ”e” in your field of view and then rotate the
nosepiece to 10X
• 8- Use the fine adjustment knob to focus until the image is
sharp. Draw the image. Do not use the coarse adjustment
• 10- Rotate the nosepiece until the 40X. Draw the image
CARES OF THE MICROSCOPE
• When moving the microscope, carry it with 2 hands (one
hand to grip the arm and the other under the base
• Lenses have to be clean with lens paper (to keep them
free of oil and dust).
• Do not use the coarse adjustment when focusing with
the higher power objectives
THE END