Unit 1: Homeostasis & the Cell

HomeostasisHomeostasisThe body’s ability to maintain a stable internal (inside) environment, while the external (outside) environment is changing.

Outside Temperature: 25° F Outside Temperature: 95° F

Inside Body Temperature: 98.6° F

Levels of OrganizationLevels 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…

– D K P C O F G S

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Cell MembraneCell Membrane

The cell membrane is flexibleflexible and allows a unicellular organism to move

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Functions of Plasma Functions of Plasma MembraneMembrane

Protective barrierProtective barrier

Regulate transport in & out of Regulate transport in & out of cell cell (selectively permeable)(selectively permeable)

Allow cell recognitionAllow cell recognition

Provide anchoring sites for Provide anchoring sites for filaments filaments of cytoskeletonof cytoskeleton

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Structure of the Cell Structure of the Cell MembraneMembrane

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PhospholipidsPhospholipids

Make up the cell membrane

Contains 2 fatty acid chains that are nonpolarHead is polar & contains a Phosphate group

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Polar heads are hydrophilichydrophilic “water loving”Nonpolar tails are hydrophobichydrophobic “water fearing”

Cell MembraneCell Membrane

Makes membrane “Selective” in what crosses

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Types of Transport Types of Transport Across Cell Across Cell MembranesMembranes

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Simple DiffusionSimple Diffusion

• Requires NONO energy

• Molecules move from area of HIGH to LOWHIGH to LOW concentration

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DIFFUSIONDIFFUSION

Diffusion is a PASSIVEPASSIVE process which means no energy is used to make the molecules move.

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OsmosisOsmosis

• Diffusion of waterDiffusion of water across a membraneacross a membrane

• Moves from Moves from HIGH HIGH Concentration to a Concentration to a LOW concentrationLOW concentration

Diffusion across a membrane

Semipermeable

membrane

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Cell in Isotonic SolutionCell in Isotonic Solution

CELLCELL

10% NaCL90% H2O

10% NaCL

90% H2O

What is the direction of water movement?The cell is at _______________.equilibrium

ENVIRONMENTENVIRONMENT

NO NET NO NET MOVEMENMOVEMENTT

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Cell in Hypotonic Cell in Hypotonic SolutionSolution

CELLCELL

10% NaCL90% H2O

20% NaCL

80% H2O

What is the direction of water movement?

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Cell in Hypertonic Cell in Hypertonic SolutionSolution

CELLCELL

15% NaCL85% H2O

5% NaCL95% H2O

What is the direction of water movement?

ENVIRONMENTENVIRONMENT

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Passive Passive TransportTransport

Simple DiffusionSimple Diffusion

Doesn’t require Doesn’t require energyenergy

Moves high to low Moves high to low concentrationconcentration Example: Oxygen Example: Oxygen diffusing in or carbon diffusing in or carbon dioxide diffusing outdioxide diffusing out.

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Passive Passive TransportTransport

Facilitated diffusion

Doesn’t require energy

Uses transport proteins to move high to low concentrationExamples: Glucose or Examples: Glucose or amino acids moving amino acids moving from blood into a from blood into a cell.cell.

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Active TransportActive Transport

Requires energy or ATP

Moves materials from LOW to HIGH concentration

AGAINST concentration gradient

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Moving the “Big Stuff”Moving the “Big Stuff”

Molecules are moved out of the cell by vesicles Molecules are moved out of the cell by vesicles that fuse with the plasma membrane.that fuse with the plasma membrane.

ExocytosisExocytosis-

moving things out.

This is how many hormones are secreted and how nerve cells This is how many hormones are secreted and how nerve cells communicate with one anothercommunicate with one another.

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Moving the “Big Moving the “Big Stuff”Stuff”Large molecules move materials into the Large molecules move materials into the

cell by one of three forms of endocytosiscell by one of three forms of endocytosis.

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

Covalent Bond

Hydrogen Bond

Properties of Water

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

Cohesion, Adhesion and Surface Tension

Properties of WaterIn 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.”

High Heat Capacity

Types of Biological Molecules

1. Many biological molecules are polymersA. 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 substancesA. lipids are a heterogeneous group of compounds

defined by solubility, not structureD. 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 monomersA. proteins have great structural diversity and

perform many rolesB. 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

proteins2. 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)

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What Are Enzymes?What Are Enzymes?• Most enzymes

are Proteins Proteins ((tertiary and quaternary structures)

• Act as CatalystCatalyst to accelerate a reaction

• Not permanentlyNot permanently changed in the process

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 arterieso Carry blood away from the heart to the lungso Carry deoxygenated blood

• Pulmonary Veinso 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

EXHALATIONAs 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

• Systemico 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

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The urinary system

• Fig. 16.1

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 upSodium enters the axonAxon becomes more positive

REPOLARIZATION Potassium gates openK+ moves outside of axonAxon 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