Biology 2nd Quarter (Ppt Notes)

8/3/2019 Biology 2nd Quarter (Ppt Notes)

http://slidepdf.com/reader/full/biology-2nd-quarter-ppt-notes 1/6

Amica !

Rain orwaves

Dilute

solutions of monomers

LAVAProteinoids

andpolymers

water

Biology 2nd

Quarter

I. Origin of Life

A. Formation of the Universe

Big Bang Theory

- massive blast allowed all the universe's known

matter and energy—even space and time

themselves—to spring from some ancient and

unknown type of energy

B. Formation of The Solar System

Explosion of a Super Nova

- disturbed cloud of gas and dust

- cloud grew hotter and denser in the center (hot

center, cool edges)

C. Formation of the Earth

Alexander Oparin

- One of the two scientists who independently

hypothesized the abiotic formation of organic

compounds

JBS Haldane

- One of the two scientists who independently

hypothesized the abiotic formation of organic

compounds

Prebiotic Soup

- Abiotic synthesis of small organic molecules

amino acids and nucleotides

Why Spontaneous Generation cannot happen today:

1. because atmosphere is oxygen rich2. oxidizing atmosphere today not conducive

3. o2 attacks chemical bonds extracting electrons

4. less UV radiation that helps in forming organic

molecules

Harold Urey

- One of two scientists who tested the Oparin-

Haldane Hypothesis

- Teacher

Stanley Miller

- One of two scientists who tested the Oparin-Haldane Hypothesis

- Student

Experiment:

Early atmosphere - H2O, H2, CH4, NH3, CO, CO2,

N2, water vapour

The experiment had produced - 20 Amino acids

found in organisms, sugars, lipids, purines,

pyrimidines, even ATP

** Lab simulations of the early earth conditions produced

organic polymers

** Natural process in organisms: Enzymes catalyze reactions

Sydney Fox

- Protenoids: polypeptides from abiotic means

J. Bernal

- Prebiotic synthesis of polymers took place on

clay

A. G. Cains-Smith

- clays might have been the first templates for

self-replicating systems

- Pyrite: Charged surface

Protobionts- Aggregates of abiotically produced molecules

that can’t reproduce precisely

RNA

- first genetic material

- short polymers of ribonucleotides have been

produced abiotically in the laboratory



Amica !

- revolution thinking about the evolution of life

when they discovered that RNA molecules are

important catalysts in modern cells

- ribosomes use rna catalyts: rRNA, tRNA and

mRNA

- capable of self replication

5 Descriptions of FIRST LIFE1. Unicellular

2. Asexually reproducing

3. Aquatic environment

4. RNA containing

5. Heterotrophic

II. Cell: Organic Unit of Life

Cell

- basic unit of structure and function

- Can be:

o Unicellular

o Multicellular - Bodies are cooperative of

specialized cells; Cannot survive for long on

their own

How do we study cells?

- Telescope // Microscope

- Anton von Leeuwenhoek: first to explore

things: microscopic view

ESSENTIAL SCIENTISTS

a. Robert Hooke

- Cells composed of thousands of chambers

b. Robert Bown

- Nucleus: Dark structure

c. Matthias Schleiden

- all plants are made up of cells

d. Theodor Schwann

- all animals are made up of cells

e. Rudolf Virchow

- Cells arise from the division of pre-existing cells

CELL THEORY most fundamental discovery: nature of living things

forms basic framework

formulated by Schwann, Schleiden and Virchow

States that:

all living things are composed of cells

cells are the basic unit of structure and function

all cells come from pre-existing cells

PROKARYOTIC VS EUKARYOTIC

ORGANELLES

Nucleus

- contains most of the genes

*Nuclear envelope

> Encloses nucleus

> Double membrane (lipid bilayer with proteins)

Nuclear lamina - netlike array of protein

filaments maintains the shape of the nucleus

Nucleolus - Site: components of ribosomes are

synthesized and assembled; Components pass

through the nuclear pore to the cytoplasm;

Appears as a mass of densely stained granules

and fibers adjusting part of chromatin

Ribosomes

- Protein factory

- cells with active protein synthesis

- prominent nucleoli

- Free ribosomes: cytosol

- Bound ribosomes: for inclusion, transport,

packaging

ENDOMEMBRANE SYSTEM

Membranes that are related either: direct physical

continuity or transfer of membrane segments

Includes: VAly PLAne GOer

Nuclear Envelope, ER, Golgi Apparatus, Lysosomes,

Vacuoles, Plasma Membrane

Endoplasmic Reticulum

- more than half the total membrane of cells

- reticulum Greek word for network

a. Smooth ER

o Smooth walls of the sacs are not studded

with ribosomes

o Functions: SYLIP me car DE DRUP

Synthesis of lipids

Metabolism of carbohydrates

Detoxification of drugs and poison

b. Rough ER

o studded with ribosomes

PROKARYOTIC

Pro- before

Karyon- kernel

no nucleus

DNA: concentrated in

a NUCLEOID With cytoplasm

w/ Plasma Membrane

EUKARYOTIC

Eu- true

Karyon- kernel

Has NUCLEUS

With cytoplasm

Cytosol w/ Plasma Membrane



Amica !

o Functions:

synthesis of secretory protein

membrane production

synthesis of proteins

Golgi Apparatus

- Center of: MWSS

Manufacturing

Warehousing

Sorting

Shipping

- Products from the ER are: SMS

Modified

Stored

Sent to other destinations

Vacuoles

- membrane bound sacs in a cell

- Repository of inorganic ions

- Storage of pigments

- Helps to protect against predators

- food vacuole- formed by phagocytosis

- Contractile vacuole

Pumps out water out

- Central Vacuole- filled with liquid

Tonoplast

organic compounds (proteins in seed)

Disposal sites for metabolic products

Lysosomes

- membrane bounded sacs of hydrolytic enzymes

- digestion of macromolecules

- works best in acidic medium ~pH 5

- maintains internal pH

- excessive leak of a large number

- leads to auto digestion

Plasma Membrane

- Controls traffic into and out of the cell

- Selective permeable

- Membrane structure:

Charles Overton - it is made of lipids

- RBC- composed of lipids and proteins

- made up of phospholipids

- Amphiphatic

Irvin Langmuir - Artificial membranes;

Phospholipids in benzene* + water

Gunter and F. Grendel - phospholipid bilayer;

Suggests: stable boundary between two

aqueous compartments; Measured lipid

content in RBC

S.J. Singer and G. Nicolson – Fluid Mosaic

Model: mosaic of protein molecules in a fluid

bilayer of phospholipids

OTHER MEMBRANE ORGANELLES

not part of Endo-Membrane System

membranes not made by ER

Free ribosomes and Ribomes of Mitochondria

and Cytoplasm

contain small amounts of DNA

semi- autonomous

Mitochondria

- power house of the cell

- site of cellular respiration

Catabolic process that generates ATP

- number related to cell’s metabolic activity

- enclosed by two membranes

Outer- smooth

Inner- convoluted with infoldings (cristae)

Chloroplast

- found in plants and eukaryotic algae

- site of photosynthesis

- Solar energy chemical energy

- member of plastids

- Amyloplasts- colorless, stores starch

- Chromoplast- stores pigments

- contains another membranous system

THYLAKOIDS

- flattened sacs

- forms GRANA- bathed with stroma

Peroxisomes

- specialized metabolic compartment bounded

by a single membrane

- sontains enzymes that produces* H2O2 as a by

product

- Function:

Use O2 to break Fatty acids

Detoxify alcohol

Transferring H2 from the poisons to oxygen

Cytoskeleton

- Organization of structures and its activities

- Mechanical support

- Maintains shape

Important to animal cells

- Anchorage for organelles

- cell motility

3 MAIN TYPES of FIBERS



Amica !

Microtubules - Straight hollow rods; Made from

Tubulin; Shape and support; Tracks for

organelles equipped with motor proteins;

Involved in cell division

Cilia and Flagella - Core of microtubules

sheathed in an extension of the Plasma Mem.

Microfilaments - Solid rods; bear tension

Cell Wall

- Plant cells only

- Protection

- Maintains shape

- Prevents excessive uptake of water

- Made up of cellulose

Extracellular Matrix

- Support; Adhesion; Movement; Regulation

- Components:

Collagen: forms strong fibers outside the cell;

Protein rich in carbohydrates

Fibronectin: attached to the ECM; Bind to

receptor proteins – INTEGRIN*

- Regulate cell behavior

- Influence activity of genes

III. Terms in Microscopy

Magnification

- how much larger the object appears compared

to pts real size

Resolving power

- Measure of the clarity of the image

- Minimum distance two points can be separated

and still be distinguished as 2 separate points

Resolution

- Limited by the wavelength of light used to

illuminate the specimen

TYPES OF MICROSCOPES

a. Light Microscopes

- visible light is passed through the specimen

- lenses: refract light (image is magnified)

- can magnify effectively to about 1000x the size

of actual specimen

b. Electron Microscope

- focuses beam of electrons

- uses shorter wavelengths

- Resolution power: inversely proportional to the

wavelength of radiation

Transmission Electron Microscope

o aims an electron beam through a thin

specimen

o Uses electromagnets

o image is focused on a screen or on

photographic film

o heavy metals for staining

Scanning Electron Microscope

- detailed study of the surface of specimen

- electron beam scans the surface

- coated with thin film of gold

- electron beam excites the electron on the

sample’s surface

IV. Disease

Disease

- any change (other than an injury) that interferes with

the normal body function

- impair normal tissue function

Infectious Disease- caused by infectious agents

- acquired: contact w someone carrying disease;

contaminated objects, food, air

- Spread: olio virus contaious not virulent bola

hemorrhaic fever virulent not contaious

D: results from the invasion and growth of a pathogen; tissue

function is impaired

I: results when a pathogen invades and begins growing within a

host; bodily function: normal

Can be:

a. Genetic (Cystic fibrosis, Hemophilia)

b.

Aging (Atherocslerosis, osteoporosis)c. Infectious (German measles, Chicken pox, Malaria)

Pathogens

- microorganisms that are capable of causing disease

- infectious agent that causes disease in virtually any

susceptible host

Opportunistic Pathogens

- potentially infectious agents

- Found on

elderly immuno suppressed

cancer patients immuno- compromised

people who have AIDS or are HIV-positive (immuno-

compromised

Types:

a. Viral Infections (colds, influenza, measles, chicken

pox, West Nile virus, hepatitis, AIDS)

b. Bacterial infection (pneumonia, strep throat, boils,

acne, streptococcal infection, bubonic plague, and

anthrax)

c. Protozoan infections (Malaria, amoebiasis and

Diarrhea)



Amica !

d. Fungal infections (yeast infections, ringworm and

athlete's foot)

e. Helminthes Infection - simple, invertebrate animals,

some of which are infectious parasites

(Schistosomiasis Liver fluke disease)

How they harm the host...

1. enter the host body

2. adhere to specific host cells (invade and colonize)

3. multiply between host cells or within body fluids

(cause tissue damage)

4. production of toxins or destructive enzymes

Germ Theory

- states that microorganisms can cause diseases

- infectious disease is caused by an infectious agent

Robert Koch

- use of agar as solid medium.

- invented nutrient broth and nutrient agar

Modes of Infection:

a.

Direct contact with reservoirb. Indirect contact - when a pathogen can

withstand the environment outside its host

for a long period of time before infecting

another individual

c. ir - borne droplet infection colds, flu,

sinus infections, German measles

d. ectors - carry disease throuh other

animals e insect bites typhus, rabies, H-

fever, malaria, dengue

Defense:

Structural Defense

- Skin, mucous membranes

-

perspiration salts and fatty acids- tears contain lysoyme hich can brea don

bacterial cell all

- acid secretion in stomach l

Cellular

- Phagocytosis (leucocytes in WBC)

Specific mechanisms of host resistance

- white blood cells called lymphocytes:

- -cells produced from lymphocytes that matured in

the thymus land

- B-cells (produced from lymphocytes that matured in

the bone marrow)

V. Viruses

Virus

- infectious agent (parasites of animals, plants and

some bacteria)

- parasitic non-cellular particle

- Consists of: nucleic acid core -protein coat

- metabolism and reproduction: needs living cell / host

Reproduction

1. initiates the synthesis of viral proteins

2. undergoes replication

3. new viruses are released

VIRUS VS. FREE LIVING CELL

VIRUS

• Acellular

• can not live independently• Either DNA or RNA

FREE LIVING CELL

• can grow, reproduce, regulate gene expression

• can evolve independently

Tobacco Mosaic Virus

- bleached spots that form a pattern that farmers

called a mosaic

- leaves turn yellow, wither and fall off, killing the plant

Dimitri Iwanowski- juice taken from diseased plants

- placed extract on the leaves of healthy plants

- healthy plants became infected

Martinus Beijerinck

- named the disease causin particle “virus” Latin for

poison

Wendell Stanley

- chemically isolates and identifies the disease causing

particle as the Tobacco Mosaic Virus (TMV)

- through electron microscopy

BASIC STRUCTURE



Amica !

CLASSIFICATION OF VIRUSES

a. Genetic Material – DNA or RNA (never both)

b. Shape

c. Size

d. Presence of Envelope - enveloped viruses enclosed by a

membrane (portion of host cell or nuclear membrane)

e. Specificity

f. Disease Type

Prions

- Infectious proteins

- Scrapie in sheep

- Creutzfeldt Jacob Disease- humans

Viroids

- Naked circular molecules of RNA that infect plants

- Disrupts plants metabolism

LIFE CYCLE

1. Infection - chance of contact

2. Growth - DNA of the virusRNA polymerase viral mRNAwrecking crew

3. Replication - 25min (in E. coli

Lysogenic cycle – temperate/ avirulent phage

IMPORTANCE OF VIRUS

Pathogenic

- Defense vs. viral infection

- Discovery of vaccines

ORIGIN OF VIRUSES

• Pieces of cellular DNA became a part of an infectious

particle

• Not likely to have been the 1st

living things on earth

• Evolved from the genetic material of living cells

Documents

Biology 2nd Quarter (Ppt Notes)