Transcript Biology REview pP - Westgate Mennonite Collegiate

Unit 1: Homeostasis & the Cell
Homeostasis
The body’s ability to maintain a
stable internal (inside) environment,
while the external (outside)
environment is changing.
Inside Body Temperature: 98.6° F
Outside Temperature: 25° F
Outside Temperature: 95° F
Levels of Organization
Cells
Tissues
Organs
Organ
Systems
The modern system of classification has 8
levels:
• Domain
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species
Helpful way to remember the 8 levels
• Dumb kids playing catch on freeways get
squashed
• Or…make up your own…
–DKPCOFGS
Cell Membrane
The cell
membrane is
flexible and
allows a
unicellular
organism to
move
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Functions of Plasma Membrane
 Protective barrier
 Regulate transport in & out of cell
(selectively permeable)
 Allow cell recognition
 Provide anchoring sites for filaments
of cytoskeleton
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Structure of the Cell
Membrane
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Phospholipids
Make up the cell
membrane
Contains 2 fatty
acid chains that
are nonpolar
Head is polar &
contains a
Phosphate group
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Cell Membrane
Polar heads are hydrophilic “water loving”
Nonpolar tails are hydrophobic “water fearing”
Makes membrane “Selective” in what crosses
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Types of Transport
Across Cell Membranes
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Simple Diffusion
• Requires NO
energy
• Molecules move
from area of
HIGH to LOW
concentration
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DIFFUSION
Diffusion is a PASSIVE
process which
means no energy is
used to make the
molecules move.
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Osmosis
Diffusion across a membrane
• Diffusion of water
across a membrane
• Moves from HIGH
Concentration to a
LOW concentration
Semipermeable
membrane
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Cell in Isotonic Solution
10% NaCL
90% H2O
ENVIRONMENT
CELL
10% NaCL
90% H2O
NO NET
MOVEMENT
What is the direction of water movement?
equilibrium
The cell is at _______________.
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Cell in Hypotonic Solution
10% NaCL
90% H2O
CELL
20% NaCL
80% H2O
What is the direction of water movement?
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Cell in Hypertonic Solution
15% NaCL
85% H2O
ENVIRONMENT
CELL
5% NaCL
95% H2O
What is the direction of water movement?
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Passive Transport
Simple Diffusion
 Doesn’t require energy
 Moves high to low
concentration
 Example: Oxygen
diffusing in or carbon
dioxide diffusing out.
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Passive Transport
Facilitated diffusion
Doesn’t require energy
Uses transport
proteins to move high to
low concentration
Examples: Glucose or
amino acids moving from
blood into a cell.
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Active Transport
Requires energy or
ATP
Moves materials from
LOW to HIGH
concentration
AGAINST
concentration gradient
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Moving the “Big Stuff”
Exocytosis-
moving
things
out.
Molecules are moved out of the cell by vesicles that fuse
with the plasma membrane.
This is how many hormones are secreted and how nerve cells communicate
with one another.
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Moving the “Big Stuff”
Large molecules move materials into the cell by
one of three forms of endocytosis.
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Unit 2: Biochemistry
Molecules and Compounds
• Ionic Bonding
– Non-metal and metal
– Electrons are transferred from one atom to
another (high ΔEN)
– Goal is to have a complete valence shell
• Covalent Bonding
– Two non-metals
– Electrons are shared between two atoms
Molecules and Compounds
– Polar vs. Nonpolar Covalent Bonds
• Electrons are shared, but they may not be shared
equally
• Polar molecules are hydrophilic (water loving)
• Non-polar are hydrophobic (water fearing)
– Amphipathic
• Polar and non-polar ends
Properties of Water
Covalent bonding
Polar covalent bond – unequal sharing of
electrons
A great example of a molecule with polar
covalent bonds is water. Why is water
considered polar?
What is a partial positive and partial
negative charge?
Properties of Water
Covalent bonding vs. Hydrogen bonding
Hydrogen Bond
Covalent Bond
Properties of Water
Cohesion, Adhesion and Surface Tension
cohesion = water attracted to other water
molecules because of polar properties
adhesion = water attracted to other materials
surface tension = water is pulled together creating
the smallest surface area possible
Properties of Water
High Heat Capacity
In order to raise the temperature of
water, the average molecular speed
has to increase.
It takes much more energy to raise
the temperature of water compared to
other solvents because hydrogen
bonds hold the water molecules
together!
Water has a high heat capacity.
“The specific heat is the amount of
heat per unit mass required to raise
the temperature by one degree
Celsius.”
Types of Biological Molecules
1. Many biological molecules are polymers
A. polymers are long chains or branching chains
based on repeating subunits (monomers)
• example: proteins (the polymer) are made from amino
acids (the monomers)
• example: nucleic acids (the polymer) are made from
nucleotides (the monomers
Types of Biological Molecules
2. The four major classes of biologically
important organic molecules are:
• carbohydrates
• lipids
• proteins or polypeptides (and related
compounds)
• nucleic acids (and related compounds)
Carbohydrates
Carbohydrates include sugars, starches, and
cellulose
carbohydrates contain only the elements
carbon, hydrogen, and oxygen
Carbohydrates
• glycogen is the main storage
carbohydrate of animals
 similar to starch, but very highly
branched and more water-soluble
 is NOT stored in an organelle; mostly
found in liver and muscle cells
Lipids
IV. lipids are fats and fat-like substances
A. lipids are a heterogeneous group of compounds
defined by solubility, not structure
D. roles of lipids include serving as membrane
structural components, as signaling molecules,
and as energy storage molecules
E. major classes of lipids that you need to know are
triacylglycerols (fats), phospholipids, and
steroids
Proteins
V. proteins are macromolecules that are
polymers formed from amino acids monomers
A. proteins have great structural diversity and
perform many roles
B. roles include enzyme catalysis, defense,
transport, structure/support, motion, regulation;
protein structure determines protein function
C. proteins are polymers made of amino acid
monomers linked together by peptide bonds
Protein Denaturation
7. denaturation is unfolding of a protein, disrupting of
structure
• changes in temperature, pH, or exposure to various
chemicals can cause denaturation
• denatured proteins typically cannot perform their
normal biological function
• denaturation is generally irreversible
Nucleic Acids
VI. nucleic acids transmit hereditary information
by determining what proteins a cell makes
A. two classes of nucleic acids found in cells:
deoxyribonucleic acid (DNA) and ribonucleic acid
(RNA)
1. DNA carries the genetic information cells use to make
proteins
2. RNA functions in protein synthesis according to
mechanisms
DNA vs. RNA
C. DNA typically contains the purines adenine (A)
and guanine (G), and the pyrimidines cytosine
(C) and thymine (T)
D. RNA typically contains the purines adenine (A)
and guanine (G), and the pyrimidines cytosine
(C) and uracil (U)
Lipids
• Two general categories of fatty acids:
– Unsaturated fatty acids
• Liquid at room temp.
• Oils, plant fats (generally)
– Saturated fatty acids
• Solid at room temp.
• Butter, animal fats (generally)
What Are Enzymes?
• Most enzymes
are Proteins
(tertiary and
quaternary
structures)
• Act as Catalyst
to accelerate a
reaction
• Not permanently
changed in the
process
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Unit 3: Digestion & Nutrition
Unit 4: Circulatory System
Cardiovascular System
• Pathway of blood through the heart
• Deoxygenated Blood
– superior vena cava, inferior vena cava,
right atrium, right ventrical, pulmonary
artery
• Blood received oxygen from lungs
• Oxygenated Blood
– Pulmonary vein, left atrium, left ventrical,
aorta
Cardiovascular System
• Pulmonary arteries
o Carry blood away from the heart to the lungs
o Carry deoxygenated blood
• Pulmonary Veins
o Carry oxygenated blood from heart to the lungs
Cardiovascular System
• Heart Beat
– Systole
• Contraction of heart muscles
– Diastole
• Relaxation of heart muscles
– Heart beat
• Number of times heart beats per minute
Cardiovascular System
• Blood Pressure
o Pressure your blood exerts against your blood vessel
walls as your heart pumps
o Systolic
• Pressure peak of heart beat
• Higher number
o Diastolic
• Pressure when heart is resting
• Lower number
• Both in mm Hg
Organs of the Respiratory System
Main organs of the
upper and lower
respiratory system
Glottis – triangular slit that opens during
breathing/talking, and closes during swallowing
Epiglottis – flaplike structure that stands upright, allows
air to enter larynx, during swallowing it presses
downward and prevents food from entering air passages
EXHALATION
As the diaphragm and other muscles relax,
ELASTIC RECOIL from surface tension
forces air out.
Muscles can force extra air out or in
Respiratory Volumes and Capacities
• Tidal Volume
– A normal breath
– Amount of air that enters the lungs during 1 cycle
• Inspiratory Volume
– Additional amount that can be forcefully inhaled after
inspiration of a normal breath (breathing in)
• Expiratory Volume
– Additional amount that can forcefully exhaled after expiration
of a normal breath (breathing out)
• Residual volume
– Air remaining in lungs even after forceful exhalation
Circulatory System
• 2 main systems of Circulatory system
• Pulmonary System
• Circulates blood through the lungs
• Systemic
o Takes oxygenated blood from the hear to the rest
of the body
The Urinary System
Functions of the Urinary System
•
•
•
•
1. Excretion of Metabolic Wastes
2. Maintenance of Water-Salt Balance
3. Maintenance of Acid-Base Balance
4. Secretion of Hormones
The urinary system
• Fig. 16.1
16-57
Organs of the Urinary system
• While the bladder is filling:
– the detrusor muscle is relaxed so the bladder
wall can expand and the sphincter muscles are
contracted to keep the urethra closed
• When the bladder empties:
– the detrusor muscle contracts to squeeze the
urine out, and the sphincter muscles relax so
the urethra can open up
Anatomy of a nephron
Urine formation
• 1. Glomerular Filtration
– Blood enters the afferent arteriole into the
glomerulus
– Here water and small molecules are filtered into
Bowman’s capsule
• Water, nutrients, salts, waste molecules are filtered
and called the filtrate
• Large molecules like blood cells and platelets can’t
pass through and exit vis efferent arteriole
Urine formation
• 2. Tubular Reabsorption
– From Bowman’s Capsule the filtrate enters
proximal convoluted tubule
– Here molecules from the filtrate are reabsorbed
back into the blood of the capillary network
– This is important because:
• our body must reabsorb nutrients and water is back
into the body so it can function properly
Urine formation
• 3. Tubular Secretion
– From the PCT the filtrate enters the Loop of
Henle, and then finally into the distal convoluted
tubule where secretion occurs
• Here wastes from the blood that were not filtered
through Bowman’s capsule enter the tubule
• Ammonia and many drugs are removed from the
blood during secretion
– From here it travels to the collecting duct where
it is transported out of the body via the bladder
ADH
• Antidiuretics mean decreased amount of
urine
• ADH causes the collecting duct becomes permeable
to water
• Water diffuses out of the collecting duct
– Less urine, and more concentrated
• More ADH is produced at night
Alcohol affects
Alcohol suppresses ADH production by
the pituitary
Without ADH, higher amounts of water
stay in the urine
Urine with high concentrations of water
leaves the body
The Nervous System
Neurons DIAGRAM
Nerve Impulse
Action potential
 Rapid change in polarity across the axon
 Nerve impulse
During an action potential
 DEPOLARIZATION
Sodium channels open up
Sodium enters the axon
Axon becomes more positive
 REPOLARIZATION
Potassium gates open
K+ moves outside of axon
Axon returns to original negative charge
The Brain
• The four major parts of the brain (in order of
highest to lowest functioning)
– the cerebrum
– the diencephalon
– the cerebellum
– the brain stem
The Brain
• Brain divided into 4 lobes
– Frontal Lobe
• reasoning, motor skills, higher level cognition, and
expressive language.
– Parietal Lobe
• Sensory information
– Temporal Lobe
• Hearing, formation of memories
– Occipital lobe
• Vision, interpreting vision
Peripheral Nervous System
• 2 parts
– Somatic
– Autonomic
• 2 divisions
– Sympathetic – fight or flight
– Parasympathetic – rest and digest