I ADDED TISSUES JUST IN CASE!!!
APHY 101, Lecture 4
Metabolism
1. Anabolism (add)
a. Large molecules are synthesized from smaller molecules
b. Dehydration Synthesis – H2O is released when bonds are formed
 Connects monosaccharides to form polysaccharides
 Connects fatty acids to glycerol
 Joins nucleotides together
 Joins amino acids together = peptide bonds
2. Catabolism (cut)
a. Reverse of anabolism
b. Large molecules are broken down into smaller molecules
c. Hydrolysis reaction – requires H2O to break molecules
 Breaks down polysaccharides into monosaccharides & disaccharides
 Removes fatty acids from glycerol
 Breaks down polypeptides into amino acids
 Breaks down nucleic acids into nucleotides
3. Requirements for reactions
a. Activation energy
 Energy needed to start a reaction-may be heat
b. Enzymes
 Characteristics of enzymes
1. Almost always proteins
2. Catalyze (speed up) reactions
3. Reusable-not consumed by reaction
4. Anabolic & catabolic reactions require different enzymes
5. Specificity- each enzyme acts only on one molecule or substance
6. End in ___ase
7. Examples:
a. Lipase digests lipids
b. Protease digests proteins
4.
5. Limitations of Reactions
a. Concentration of substrate limits rate of reaction
b. Concentration of enzyme limits rate of reaction
c. Efficiency of enzyme also limits the rate of reaction
6. Metabolic Pathway
a. Cascade of several reaction, each step controlled by an enzyme
7.
Rate-limiting Enzyme
a. Determines rate of reaction
b. Least efficient enzyme in metabolic pathway
c. Usually first reaction in sequence (example: enzyme A in above pathway)
8. Cofactor
a. Non-protein
b. Combines with & activates enzyme
c. Exposes active site of enzyme to substrate
d. Includes ions, vitamins, organic molecules
9. Coenzyme
a. Organic molecule or vitamin that acts as a cofactor
Energy for metabolic reactions
1. Energy = capacity to change something, or to do work
a. Examples of energy: heat, sound, light, electrical, chemical, mechanical
b. Energy cannot be created or destroyed. Only changed or transferred
2. Cellular Respiration
a. Transfer of energy from chemical bonds of molecules to make available for cellular use
b. Oxidation reaction- controlled burning of molecules. Chemical bonds are broken releasing
energy. Energy is used by cells.
3. Adenosine Triphosphate (ATP)
a. Currency of energy for cells
b. Nucleotide with 3 high energy phosphate bonds
c.
d. Phosphate bond can be broken, releasing energy for cell
 Hydrolysis reaction releases Phosphate & transfers energy
 Product = Adenosine Diphosphate (ADP)

e. Phosphate bond can be added to ADP to reuse ATP
 Phosphorylation = adding phosphate to ADP
 Requires energy to add Phosphate to ADP
 Makes ATP reusable

Phosphorylation:
Hydrolysis:
ADP + Phosphate + Energy →
ATP
ATP →
ATP + Phosphate + Energy
Cellular Respiration
1. Anaerobic
a. Does not require Oxygen
b. Makes only little energy (ATP)
2. Aerobic
a. Requires Oxygen
b. Makes much energy (ATP)
c. Respiration Reaction: C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
3. Respiration occurs in stepwise manner to trap energy
a. Steps of Respiration
1.
Glycolysis
2.
Conversion of pyruvate into Acetyl CoA
3.
Citric Acid Cycle
4.
Electron Transport Chain
4. Energy is obtained from the transfer of electrons from one molecule to another molecule
 Electrons transferred in pairs (: = 2electrons)

Requires electron carrier molecules
1. NADH
NAD+ + 2H: → NADH: + H+
2. FADH2

(NADH: carries electrons)
FAD + 2H: → FADH2:
(FADH2: carries electrons)
NADH & FADH2 carry electrons from metabolic reactions to electron transport chain
APHY 101, Lecture 5
Energy for metabolic reactions
4. Adenosine Triphosphate (ATP)
a. Currency of energy for cells
b. Nucleotide with 3 high energy phosphate bonds
c.
d. Phosphate bond can be broken, releasing energy for cell
 Hydrolysis reaction releases Phosphate & transfers energy
 Product = Adenosine Diphosphate (ADP)

e. Phosphate bond can be added to ADP to reuse ATP
 Phosphorylation = adding phosphate to ADP
 Requires energy to add Phosphate to ADP
 Makes ATP reusable

ADP + Phosphate + Energy →
ATP
ATP →
ATP + Phosphate + Energy
Phosphorylation:
Hydrolysis:
Cellular Respiration
5. Anaerobic
a. Does not require Oxygen
b. Makes only little energy (ATP)
6. Aerobic
a. Requires Oxygen
b. Makes much energy (ATP)
c. Respiration Reaction: C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
7. Respiration occurs in stepwise manner to trap energy
a. Steps of Respiration
5.
Glycolysis
6.
Conversion of pyruvate into Acetyl CoA
7.
Citric Acid Cycle
8.
Electron Transport Chain
8. Energy is obtained from the transfer of electrons from one molecule to another molecule
 Electrons transferred in pairs (: = 2electrons)
 Requires electron carrier molecules
2. NADH
NAD+ + 2H: → NADH: + H+
3. FADH2

(NADH: carries electrons)
FAD + 2H: → FADH2:
(FADH2: carries electrons)
NADH & FADH2 carry electrons from metabolic reactions to electron transport chain (ETC)
Glycolysis
1. Breaking of glucose
2. Occurs in cytosol
3. Anaerobic
4. Yields:
a. 2 ATP (net gain)
b. 1 NADH molecule
c. 2 Pyruvic Acids
5. Reaction
a. Phosphorylation of Glucose
i. Requires 2 ATP
ii.
b. Cleavage of glucose
i. 6 Carbon glucose molecule is broken in a series of reactions into 2 Pyruvic Acid
molecules, with 3 Carbons each
ii. Yields
1. 1 NADH molecule (Carries 2 electrons to ETC)
2. 2 ATP molecules (4 ATP – 2ATP = 2ATP net gain)
3. 2 Pyruvic Acids=high energy molecules
Synthesis of Acetyl CoA
1. Aerobic Reaction
2. Occurs within Mitochondria
3. Primes 3 Carbon Pyruvic Acid for Citric Acid Cycle
4. Reaction
 3 Carbon Pyruvic Acid is decomposed into 2 Carbon Acetic Acid
o Releases 1 CO2 molecule as waste
o Releases 1 NADH molecule (carries 2 electrons to ETC)
 Acetic Acid synthesizes with Coenzyme A (CoA) → Acetyl CoA

Acetyl CoA = substrate for Citric Acid Cycle
5.
Citric Acid Cycle
1. Aerobic Reaction
2. Occurs within Mitochondria
3. Begins & ends with Oxaloacetic Acid
4. 8-9 total reactions involved
5. Reaction
a. Oxaloacetic Acid (4 Carbon) + Acetyl CoA (2 Carbon) → Citric Acid (6 Carbon)
b. Citric Acid is converted to new Oxaloacetic Acid in a series of reactions
c. Oxaloacetic Acid is used in the next Citric Acid cycle
d. Yields
i. 2 CO2 waste
ii. 1 ATP
iii. 3 NADH
iv. 1 FADH2

3 NADH + 1 FADH2 = carries 8 electrons to electron transport chain
Electron Transport Chain (ETC)
1. Occurs on inner mitochondrial membrane
a. Cristae = folding of inner membrane
2. Requires Oxygen as final electron acceptor
3. Involves 4 Proteins
a. 3 Transport Chain Complex Proteins
 Powered by e- transfer from NADH or FADH2
 Uses energy from e- transfer to power ATP Synthase
b. ATP synthase
 Enzyme
 Converts ADP + Phosphate → ATP
 Obtains energy from Transport Chain Complexes
Lipids & Proteins may also be broken down for ATP synthesis
Protein Synthesis
Sequence: DNA →transcription→ RNA → translation → Proteins
DNA replication = new DNA from existing DNA
Deoxyribonucleic Acid (DNA)
1. Double Stranded nucleic acid
 Stabilized by Hydrogen bonds
 Antiparallel
2. 4 Nitrogenous bases
a. Purines:
Adenine (A)
b. Pyrimidines: Thymine (T)
c. Complimentary Base Pairs
i. A pairs with T
ii. C pairs with G
Guinine (G)
Cytosine (C)
3. Sequence of bases encodes information for protein synthesis
Genes
1. Gene = portion of DNA that encodes for a protein
2. Genetic Code = 3 letter DNA sequence that encodes for an amino acid
3. Genome = complete set of genetic instructions for an organism
DNA Replication
1. Creates a copy of DNA molecule
2. Occurs within Nucleus
3. DNA must unwind & separate
4. Catalyzed by DNA polymerase
a. DNA polymerase uses one strand of DNA as template & adds a new 2nd DNA strand
b. Semiconservative = half of replicated DNA is new, half is original DNA
5. Steps
a. H bonds break & DNA strands separate
b. DNA Polymerase adds new DNA strand to template
c. Yields 2 new DNA strands from 1
d.
Ribonucleic Acid (RNA)
1. Single Stranded
2. Bases:
a. Adenine (A)
Uracil (U)
b. Cytosine (C)
Guinine (G)
Uracil Replaces Thymine.
A & U are Complimentary base pairs
Transcription DNA→RNA
1. Catalyzed by RNA Polymerase
2. Only 1 strand of DNA is transcribed
3. Occurs in nucleus
4. Messenger RNA (mRNA) is transcribed from DNA
5. Steps
a. Hydrogen bonds of DNA break & strands separate
b. RNA Polymerase builds mRNA using DNA as template
c. mRNA transcript is transported to ribosomes in cytoplasm
d.
mRNA transcript
1. Begins with AUG
2. Codon = 3 bases code for 1 amino acid
a. GGG = glycine
b. AUG = methionine
Translation mRNA→protein
1. Occurs on ribosomes in cytosol
a. Ribosome = ribosomal RNA + protein
2. Transfer RNA (tRNA) carries amino acids to mRNA on ribosomes
 Anticodons on tRNA bind to codons on mRNA
 Sequence of codons on mRNA determines amino acid sequence
 Ribosomes link amino acids together by peptide bonds
 tRNA releases amino acid & picks up another amino acid
TISSUES
Science of tissues = histology
4 broad tissue types
1. Muscular – contract
2. Nervous – conduct, sense, store information
3. Epithelial- forms coverings and linings
4. Connective Tissue-support, protect, transport
Junctions
Cells may be separated by matrix, or connected by junctions
1. Tight Junction
a. Membranes of adjacent cells fuse together
b. No space between cells
c. Lining of digestive tract & blood brain barrier
2. Desmosome
a. Spot welds between cells
b. Support & reinforcement
c. Epidermis
3. Gap Junctions
a. Protein Channels between cells
b. Cell to cell transport of ions
c. Intercalated discs of cardiac muscle
Epithelial Tissue
I.
Functions = protection, secretion, absorption, excretion
II.
Characteristics
a. Tightly packed
b. No blood supply
i. Nutrients reach cells by diffusion
c. Readily divide
d. Anchored to a basement membrane
e. Apical surface = faces an opening (lumen)
f. Basal surface = faces the basement membrane
III.
IV.
Classifications
a. Shape
 Squamous = flattened cells
 Cuboidal = cube shaped
 Columnar = column shaped
b. Layers
 Simple = 1 cell layer
 Stratified = more than one cell layer
Types
a. Simple Squamous Epithelium
 Diffusion & filtration
 Lines capillaries & air sacs of lungs
b. Simple Cuboidal Epithelium
 Secretion & absorption
 Lines kidneys and ducts of some glands
c. Simple Columnar epithelium

Protection, Absorption, Secretion

Lines Digestive Tract, Uterine tract

Contains Goblet Cells = secrete mucus

May contain microvilli = increases surface area of cell for absorption in digestive
system

May contain cilia
o
Cilia line simple columnar in uterine tube & propels egg
d. Stratified Squamous Epithelium
i. Many cell layers
ii. Outermost layer is squamous
iii. Outer layer of epidermis is Keratinized
1. Keratin = insoluble protein
iv. Linings of mouth, esophagus, anus, vagaina are nonkeratinized stratified squamous
epithelium
APHY 101, Lecture 6
Epithelium Tissue Continued
e. Stratified Squamous Epithelium
i. Many cell layers
ii. Outermost layer is squamous
iii. Outer layer of epidermis is Keratinized
1. Keratin = insoluble protein
iv. Linings of mouth, esophagus, anus, vagina are nonkeratinized stratified squamous
epithelium
f.
Pseudostratified Columnar Epithelium
i. Appears striated, but is actually simple
ii. Most are ciliated & have goblet cells that secrete mucus
iii. Locations
1. Lines respiratory tract
a. Mucus traps microorganisms & dust
b. Cilia convey the mucus away from lungs
g. Stratified Columnar Epithelium
i. 2-3 layers of cuboidal cells
ii. Locations:lines ducts of sweat glands, salivary glands, and pancreas
h. Transitional Epithelium
i. Location: Urinary Bladder & Uterus
ii. Forms expandable lining
1. 4-5 cell layers thick when empty
2. 2-3 cell layers thick when distended
i.
Glandular Epithelium
i. Cuboidal or Columnar
ii. Modified to Secrete substances
iii. Exocrine glands
1. Have ducts that secrete chemicals onto a surface
2. Includes sweat glands, salivary glands, goblet cells
iv. Endocrine glands
1. Ductless glands that secrete chemicals, called hormones into bloodstream
2. Includes Pituitary gland, Adrenal Glands, Thyroid glands
Connective Tissue (CT)
I.
Many Functions
I.
Binds structures, Protection, Support, Transport, Storage, Produces blood cells
II.
Characteristics
I.
Interspersed Cells
II.
Extracellular Matrix
III.
Protein Fibers
IV.
V.
Most have good blood supply
Usually Divide
III.
Cell Types
I.
Fixed – immovable cells residing in connective tissue
1.
Fibroblasts – secrete protein fibers into matrix
2.
Mast Cells – secretes histamine & heparin into bloodstream
II.
Wandering – Move throughout tissues
1.
Macrophages – phagocytize bacteria & cell debris, responds to infection
IV.
CT Fibers
I.
Produced by Fibroblasts
II.
Types
1. Collagenous Fibers
 Thick threads of collagen
 Flexible, but only slightly elastic
 Great tensile strength – resists pulling
 Forms ligaments & tendons
a. Ligaments – connect bone to bone
b. Tendons – connect muscle to bone
2. Elastic Fibers
 Spring-like protein, called elastin
 Weaker than collagen
 Easily stretched or deformed & retains shape
 Located within vocal cords, blood vessels, respiratory tract
3. Reticular Fibers
 Thin collagenous fibers
 Forms a network, called a reticulum
 Located in spleen, liver, and lymph nodes
V.
Types of Connective Tissue
I.
CT Proper
1. Loose Connective Tissue
 Areolar
 Adipose
 Reticular
2. Dense Connective Tissue
 Dense regular
 Dense irregular
 Elastic
II.
Specialized CT
1. Cartilage
2. Bone
3.
Blood
Connective Tissue Proper
I.
Loose Connective Tissues
a. Areolar Tissue
 Forms delicate membranes
 Cells = Fibroblasts
 Fibers = Collagenous & Elastic Fibers
 Locations
1. Binds Skin to organs
2. Between Muscles
b. Adipose Tissue “fat”
 Stores fat & cushions organs
 Cells = Adipocytes
 Locations:
1. Beneath skin
2. Around kidneys, eyeballs, and heart
c. Reticular CT
 Fibers = reticular fibers
 Functions = forms reticulum (network)
 Locations = Liver, spleen, lymph nodes
II.
Dense CT
a. Dense Regular CT
 Cells = fibroblasts
 Fibers = Tightly packed collagenous fibers
o Very strong to withstand pulling forces
 Locations: Ligaments & Tendons
 Poor blood supply = slow to repair
b. Dense Irregular CT
 Fibers = Collagenous fibers arranged in many directions
o Resists pulling forces from many directions
 Location = Dermis of skin
c. Elastic CT
 Elastic fibers either parallel or branching
 Some collagenous fibers & fibroblasts
 Location
1. Within walls of some hollow organs
2. Portions of airway
Specialized Connective Tissue
I.
Cartilage
a. Characteristics
i. Cells = Chondrocytes – reside in lacunae (cavities)
ii. Matrix
1. Collagenous or elastic fibers
2. Gel-like substance = protein-polysaccharide complex
iii. Lack direct blood supply = slow to heal
iv. Covered by pericardium (CT covering)
b. Types
1. Hyaline Cartilage
 Fine collagenous fibers
 Locations: ends of bones, costal cartilages of ribs, fetal skeleton
2. Elastic Cartilage
 Dense network of elastic fibers
 Locations: ears & parts of larynx
3. Fibrocartilage
 Many collagenous fibers = provides durability
 Absorbs shock
 Locations: Intervertebral discs, and knees
2. Bone
a. Characteristics
 Most rigid of all CT
 Rich in blood supply = heals quickly
 Contains Cells, Fibers, and salts
b. Matrix
 Salts = Calcium Phosphate & Calcium Carbonate
o Provides hardness
 Fibers = Collagenous Fibers
o Provides some flexibility
c. Cells
 Osteoblasts
o Deposits new matrix in concentric circles
o Surround themselves with matrix & become osteocytes
 Osteocytes
o Bone Cells
o Encased in cavity, called a Lacuna
d. Osteon
 Functional Unit of Bone
 Central Canal with Blood Vessels & Nerves
 Concentric rings = Lamellae
 Canaliculi = small canals that convey nutrients to osteocytes
3. Blood
a. Matrix = liquid Plasma
b. Cells
1.
2.
3.
Red Blood Cells – transports gasses
White Blood Cells – fight infections
Platelets- Blood Clotting
Muscle = Specialized to Contract
1. Skeletal Muscle
a. Attached to Bone
b. Moves Skeleton
c. Voluntary
d. Striated
e. Several Peripheral Nuclei
f. Long tubular cells
2. Smooth Muscle
a. Surrounds Viscera (hollow organs)
i. Blood vessels, digestive tract, reproductive tract, urinary bladder
b. Involuntary control
c. Non-striated
d. Tapered cells that form sheets
e. Single centrally located nucleus
3. Cardiac Muscle
a. Only found in heart
b. Striated
c. Branched tubes
d. Intercalated Discs
e. Single Central nucleus per cell
Nervous Tissue
o Located in brain, spinal cord, and peripheral nerves
o Consists of neurons & neuroglia
o Neuroglia = support neurons & supply neurons with nutrients
o
Neurons
 Sense & transmit impulses to other neurons, muscles, or glands
 Coordinate & regulate many body functions
Membranes
I.
Epithelial Membranes – covers body surfaces & lines body cavities
1. Serous Membrane
i. Secretes serous “watery” fluid
ii. Reduces friction
iii. Structure:
1. Mesothelium = simple squamous epithelium
2. Loose CT
iv. Locations
1. Lines body cavities & covers organs
2. Example = visceral & parietal pericardium of heart
2. Mucous Membrane
i. Lines tubes that open to outside
1. Oral & nasal cavities, digestive tract, reproductive tract, respiratory tract
ii. Structure
1. Epithelium varies
2. Loose CT
3. Goblet Cells – secrete mucus
3. Cutaneous Membrane
i. Skin
II.
Connective Tissue Membrane
1. Synovial Membrane
i. Lines joints & secretes synovial fluid
Integumentary System
o Largest Organ in Body
o Functions include:
1. Forms protective covering, slows water loss, vitamin D synthesis, temperature control
o Layers
1. Epidermis
 Outermost layer
 Stratified Squamous Epithelium
 Outer layer is keratinized
2. Dermis
 Inner layer
 Dense irregular CT, Blood Vessels, Nerves, smooth muscles, hair follicles, sweat
glands, ect.
3. Hypodermis
 Beneath skin
 Adipose Tissue & Blood vessels
Epidermis
I.
No Direct blood supply, nutrients by diffusion
II.
Layers
a. Stratum Corneum – outermost layer
i. Dead, tightly packed cells
ii. Keratinized
b. Stratum Basale – innermost layer
i. Cells near dermal layer of skin
ii. Contain Melanocytes
1. Melanocytes secrete melanin = pigment
2. All people have similar number of melanocytes, darker skin from greater melanin
secretion
3. Mutant Melanin = albinism