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AP I Exam 2 Review SlidesSummer 2013

• Lectures 7-11
• Ch. 3 and Ch. 4

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Some Definitions
Chromatin combination of DNA plus histone
proteins used to pack DNA in the cell nucleus
Gene segment of DNA that codes for a protein or
RNA - About 30,000 protein-encoding genes in
humans - DNAs instructions are ultimately
responsible for the ability of the cell to make
ALL its components

• Genome complete set of genes of an organism
• Human Genome Project was complete in 2001
• Genomes of other organisms are important also

Genetic Code method used to translate a
sequence of nucleotides of DNA into a sequence of
amino acids
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Structure of Nucleic Acids
Purines Adenine and Guanine (double
ring) Pyrimidines Cytosine, Thymine, and Uracil
(single ring)
Figure from Alberts et al., Essential Cell
Biology, Garland Press, 1998
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Structure of DNA
5'
3'
A double-stranded DNA molecule is created by
BASE-PAIRING of the nitrogenous bases via
HYDROGEN bonds. Notice the orientation of the
sugars on each stand.
5'
3'
DNA is an antiparallel, double-stranded
polynucleotide helix
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Structure of DNA
Complementary base pairing
Base pairing in DNA is VERY specific. -
Adenine only pairs with Thymine (A-T) - Guanine
only pairs with Cytosine (G-C)
Note that there are - THREE hydrogen bonds in
G-C pairs - TWO hydrogen bonds in A-T pairs - A
purine (two rings)base hydrogen bonds with a
pyrimidine base (one ring)
Figure from Martini, Human Anatomy
Physiology, Prentice Hall, 2001
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DNA Replication
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• THINGS TO NOTE
• DNA is replicated in the S phase of the cell
  cycle
• New strands are synthesized in a 5 to 3
  direction
• DNA polymerase has a proofreading function (1
  mistake in 109 nucleotides copied!)
• Semi-conservative replication describes pairing
  of post-replication strands of DNA (1 new, 1 old)

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5
3
5
3
3
5
3
Figure from Martini, Human Anatomy
Physiology, Prentice Hall, 2001
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RNA

• RNA is a polynucleotide with important
  differences from DNA
• Uses Uracil (U) rather than Thymine (T)
• Uses the pentose sugar, ribose
• Usually single-stranded
• There are three important types of RNA
• mRNA (carries code for proteins)
• tRNA (the adapter for translation)
• rRNA (forms ribosomes, for protein synthesis)

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Transciption/Translation

• Transcription
• generates mRNA from DNA
• Occurs in nucleus of the cell
• Uses ribonucleotides to synthesize mRNA
• Translation
• generates polypeptides (proteins) from mRNA
• Occurs in the cytoplasm of the cell
• Uses 3 components mRNA, tRNA w/aa, and ribosomes

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The Genetic Code

1. Codon group of three ribonucleotides found in
   mRNA that specifies an aa
2. Anticodon group of three ribonucleotides found
   in tRNA that allows specific hydrogen bonding
   with mRNA
3. AUG is a start codon and also codes for MET.
   UAA, UAG, and UGA are stop codons that terminate
   the translation of the mRNA strand.

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Find the AMINO ACID SEQUENCE that corresponds to
the following gene region on the DNA Template
-gt C T A A G T A C T Coding -gt G A T T C A T
G A
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tRNAs
Transfer RNAs (tRNA) function as adapters to
allow instructions in the form of nucleic acid to
be converted to amino acids.
Figures from Martini, Anatomy Physiology,
Prentice Hall, 2001
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Eukaryotic Genes
The template strand of DNA is the one thats
transcribed. The coding strand of DNA is used as
the complementary strand for the template strand
in DNA and looks like the codons.
Figure from Alberts et al., Essential Cell
Biology, Garland Publishing, 1998
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Eukaryotic mRNA Modification
Newly made eukaryotic mRNA molecules (primary
transcripts) undergo modification in the nucleus
prior to being exported to the cytoplasm. 1.
Introns removed2. 5' guanine cap added3.
Poly-A tail added
Figure from Alberts et al., Essential Cell
Biology, Garland Publishing, 1998
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The Fate of Proteins in the Cell

• Breakdown of proteins regulates the amount of a
  given protein that exists at any time.
• Each protein has unique lifetime, but the
  lifetimes of different proteins varies
  tremendously.
• Proteins with short life-spans, that are
  misfolded, or that become oxidized must be
  destroyed and recycled by the cell.

Enzymes that degrade proteins are called
proteases. They are hydrolytic enzymes.
Most large cytosolic proteins in eukaryotes are
degraded by enzyme complexes called proteasomes.
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Types/Functions of Epithelial Tissue

• Types of epithelium
• 1. Covering and Lining Epithelium
• External Surfaces, e.g., skin, Internal surfaces
• 2. Glandular Epithelium

• Functions of Epithelial Tissue
• Physical protection
• Control of permeability
• Secretion, Absorption, Filtration
• Provide sensation
• Provide specialized secretions (glands)

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Characteristics of Epithelial Tissue

• Specialized contacts with other cells
• Polarity (different ends of cell do different
  things)
• Avascularity (no blood supply)
• Regeneration (can divide to make new cells)
• Cellularity (lots of cells in close contact)

Remember Epithelial tissues always have a free
surface and a basement membrane
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Basal Lamina
Formerly called Basement membrane
Two components Lamina Lucida - glycoproteins
and fine protein filaments - Barrier for passage
of substances from underlying tissue
into epithelium Lamina Densa - bundles of
coarse protein fibers - gives basal lamina its
strength
Lamina thin layer
Figure from Martini, Fundamentals of Anatomy
Physiology, Benjamin Cummings, 2004
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Classification of Epithelial Tissues
Epithelial tissues are classified according to
both their

• Shape
• Squamous (Thin, flat, irregular in shape)
• Cuboidal (Square or cuboidal)
• Columnar (Rectangular, tall)
• Type of layering (stratification)
• Simple (one layer)
• Stratified (two or more layers)
• Note that classification of stratified epithelium
  is based on the shape of the superficial, not
  deep, layers

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Characteristics of Epithelial TissueSpecialized
Contacts
Tight junction forces substances to go through
cells, rather than being able to pass between
them Gap junction allow rapid passage of small
molecules/ions between cells Desmosome binds
cells together firmly so they stay connected
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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Review
NAME OF ET DESCRIPTION STRUCTURE LOCATION FUNCTION
SIMPLE SQUAMOUS a single layer of flattened cells linings of air sacs, capillaries, lymph vessels, body cavities covering ventral organs diffusion, reduction of friction
SIMPLE CUBOIDAL a single layer of cube-shaped cells with large centrally located nuclei linings of kidney tubules, ducts of glands absorption, secretion
SIMPLE COLUMNAR a single layer of tall cells with basally located nuclei, goblet cells, mucrovilli lining of intestine protection, absorption, secretion
PSEUDO- STRATIFIED COLUMNAR a single layer of tall cells with scattered nuclei, cilia, goblet cells lining of trachea, lining of fallopian tube protection, secretion
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Review
NAME OF ET DESCRIPTION STRUCTURE LOCATION FUNCTION
STRATIFIED SQUAMOUS many layers of flattened cells keratinized epidermis non-keratinized lining of vagina, anus, throat, mouth protection
TRANSITIONAL several layers of cells that change shape under pressure lining of urinary bladder and ureters Distensibility (able to stretch)
GLANDULAR simple cuboidal lining the ducts of glands secretion
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Review of Epithelial Tissues

• Glands are specialized epithelium
• Secrete on to a surface (exocrine)
• Secrete into a duct (exocrine)
• Secrete into the blood (endocrine)

• Exocrine glands have several different mechanisms
  of secretion
• Merocrine
• Release of product from vesicles by exocytosis
  none of cell is lost
• Holocrine
• Entire cell is lost packed with secretion and
  then bursts
• Ex Unicellular mucous gland multicelluar
  sweat gland, sebaceous gland, mammary gland, etc.

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Membranes
A membrane is a combination of epithelium and
connective tissue that covers and protects other
structures and tissues. Technically, then, a
membrane is an organ.

• Serous
• line body cavities that lack openings to outside
• reduce friction
• inner lining of thorax and abdomen
• cover organs of thorax and abdomen
• secrete serous fluid

• Mucous
• line tubes and organs that open to outside world
• lining of mouth, nose, throat, digestive tract,
  etc.
• secrete mucus

• Synovial
• surround joint cavities

• Cutaneous
• covers body
• skin

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Review of Connective Tissues
NAME OF CT DESCRIPTION LOCATION FUNCTION
MESENCHYME Embryo gives rise to all other CTs
AREOLAR gel-like matrix with fibroblasts, collagen and elastic fibers beneath ET (serous membranes around organs lining cavities) diffusion, cushioning organs
ADIPOSE closely packed adipocytes with nuclei pushed to one side by fats beneath skin, breasts, around kidneys eyeballs insulation, energy store, protection
RETICULAR network of reticular fibers in loose matrix basement membranes, lymphatic organs support
DENSE REGULAR dense matrix of collagen fibers tendons, ligaments attachment (high tensile strength)
DENSE IRREGULAR loose matrix of collagen fibers dermis of skin strength in several directions
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Review of Connective Tissues
NAME OF CT DESCRIPTION LOCATION FUNCTION
ELASTIC CT matrix of elastic fibers lung tissue, wall of aorta durability with stretch
HYALINE CARTILAGE chondrocytes in lacunae in amorphous matrix embryonic. skeleton, costal cart, tip of nose, trachea, larynx support
FIBRO- CARTILAGE less firm than above intervertebral discs, pubic symphysis tensile strength, shock absorber
ELASTIC CARTILAGE above plus elastic fibers external ear, epiglottis shape maintenance plus flexibility
BONE concentric circles of calcified matrix Bones support, protection, movement, Ca storage, hematopoiesis
BLOOD red cells, white cells and platelets in liquid plasma in heart and blood vessels transport of nutrients, wastes gases
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Connective Tissue (CT) Summary TableThree main
components of ALL types of CT cell, fibers,
ground substance
Name of CT Different types of this CT Main types of cells present Main types of fibers present Consistency of matrix Examples of Locations
CT Proper 1) Areolar (Loose)2) Dense regular3) Dense irregular 4) Adipose 5) Reticular 6) Elastic 1) Fibroblasts2) Fibroblasts3) Fibroblasts 4) Adipocytes 5) Fibroblasts 6) Fibroblasts 1) Collagen, Elastic 2) Collagen 3) Collagen 4) Reticular 5) Reticular 6) Elastic Semi-liquid 1) Skin, between muscles 2) Tendons, ligaments 3) Dermis 4) Body fat areas 5) Stroma of liver, spleen 6) Lungs, airways, arteries/heart
Cartilage 1) Hyaline 2) Fibrocartilage 3) Elastic (All) Chondrocytes 1) Collagen (sparse) 2) Collagen (dense) 3) Elastic All types Semi-solid, gelatinous rubbery 1) Ribs, ends of bones 2) Intervertebral disks 3) Pinna of ear, epiglottis
Bone 1) Dense 2) Spongy (All) Osteocytes Collagen Solid (hydroxyapatite) 1) Outer portions of bone 2) Inner portions of bone
Blood -- 1) RBCs2) WBCs 3) Platelets (cell fragments) Fibrinogen (soluble) Liquid Blood vessels, heart
Lymph -- Lymphocytes Reticular (in stroma of lymphoid organs) Liquid Lymph vessels
-cyte fully differentiated -blast young,
actively synthesizing cell
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Connective Tissue - Major Cell Types

• Fibroblasts
• fixed cell
• most common cell always in CT proper
• large, star-shaped
• produce fibers
• produce ground substance

• Macrophages
• wandering cell
• phagocytic
• important in defense
• derived from circulating monocytes

Mast cells are mediators of inflammation see
later
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Connective Tissue Fibers

• Collagenous fibers
• thick
• composed of collagen
• great tensile strength
• hold structures together
• abundant in dense CT
• tendons, ligaments

• Elastic fibers
• bundles of microfibrils embedded in elastin
• fibers branch
• elasticity
• vocal cords, air passages

• Reticular fibers
• very thin collagenous fibers
• highly branched
• form supportive networks

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The Ground Substance of CT
glucosamine
VERY hydrophilic! Function Very active in
controlling passage of substances through this
portion of the matrix and keeping CT hydrated
GAGs glycosaminoglycans (negatively charged
polysaccharides) a major molecule in ground
substance
Figures from Alberts et al., Essential Cell
Biology, Garland Press, 1998
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Tendons and Ligaments
Tendons Connect muscle to boneLigaments
Connect bone to boneAponeuroses Broad,
fibrous sheets usually attach muscle to muscle
(or bone)
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CT Framework of the Body
Fascia layers of fibrous connective tissue
covering and separating muscle. It connects the
organs of the dorsal and ventral cavities with
the rest of the body
Provide - Strength - Stability - Organ
position - Conduits
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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Muscle Overview

• General characteristics
• Elongated cells with special properties
• Muscle cells (myocytes) muscle fibers
• Contractile (major property of all muscle)
• Use actin (thin) and myosin (thick) for
  contraction
• Three types of muscle tissue
• Cardiac (involuntary)
• Skeletal
• Smooth

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Review of Muscle Types
NAME OF MUSCLE TISSUE DESCRIPTION OF STRUCTURE TYPE OF CONTROL LOCATION FUNCTION
SKELETAL MUSCLE long, thin fibers with many nuclei and striations Voluntary attached to bones to move bones
SMOOTH MUSCLE spindle shaped cells with one centrally located nucleus, lacking striations Involuntary walls of visceral hollow organs, irises of eyes, walls of blood vessels to move substances through passageways (i.e. food, urine, semen), constrict blood vessels, etc
CARDIAC MUSCLE a network of striated cells with one centrally located nucleus attached by intercalated discs - Intercalated disks consist of 1)gap junctions and 2) desmosomes Involuntary heart pump blood to lungs and body
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Nervous Tissue

• found in brain, spinal cord, and peripheral
  nerves

• conduction of nerve impulses

• basic cells are neurons

• sensory reception

• neuroglial cells are supporting cells

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Introduction to Inflammation
HistamineHeparin
Histamine
Restoration of tissue homeostasis after injury or
infections involves two processes, in order 1)
inflammation and 2) repair
Main signs of inflammation Redness, heat, pain,
swelling, and loss of function (Inflammation
-itis)
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001