Exam 1 Flashcards
Importance of animal cadaver and dissection
To help students understand the 3D relationship of different anatomical structures and appreciate anatomical variations
Historical aspects of animal and human cadaver dissection in science and medicine
Was expensive to obtain bodies for cadaver dissection, people would dig up graves or commit murder in order to sell bodies to medical schools, animals were often used if humans were not attainable
Anatomy Act of 1832 made this illegal, gave medical schools access to unclaimed corpses
Applications of anatomy in biomedical sciences
Dissections, pro-sections, plastinated specimens, surgery, radiology, physical examination
Topographic anatomy
Anatomic study based on regions, parts, or divisions of the body; emphasize relationships of various systemic structures
Anatomical body planes
Dorsal/ventral, medial/lateral, cranial/caudal, rostral/caudal, proximal/distal, palmar/plantar, transverse/sagittal
Relevance of enzymes in the body, organs, and as diagnostic tools
Biological catalysts that are normally proteins, primary amino acid sequence gives enzyme a tertiary structure and function
Nomenclature of enzymes
EC number or add -ase
1. Oxidoreductases
2. Transferases
3. Hydrolases
4. Lyases
5. Isomerases
6. Ligases
Nomenclature of enzymes
EC number or add -ase
1. Oxidoreductases
2. Transferases
3. Hydrolases
4. Lysases
5. Isomerases
6. Ligases
Substrate specificity
Specificity is controlled by structure - the unique fit of substrate with enzyme controls the selectivity for substrate and product yield
Enzymes selectively recognize proper substrates over other molecules
Ex: Lock-and-key model and induced-fit model
Cofactors and coenzymes
Metal ions - electrostatic bonds
Prosthetic groups - small organic molecules, permanently associated, covalent
Coenzymes - small organic molecules, water-soluble vitamins, non-covalent association/loosely bound
Interactions of substrates or analogs with enzymes
Lower the activation energy
Act in very small quantities
Rate constants change but Keq remains the same
Smaller Km = tight binding
High Km = weak binding
Vmax = theoretical maximum rate, never actually reached
Mechanisms for the control of enzyme-catalyzed reactions
Competitive inhibition: Vmax constant, Km increases
Non-competitive inhibition: Vmax decreases, Km constant
Allosteric regulation: enzymes situated at key steps in metabolic pathways are modulated by allosteric effectors that are usually produced elsewhere in the pathway; may be feed-forward activators or feedback inhibitors; usually SIGMOID
Enzymes lower activation energy by…
Forming a highly-ordered substrate in their active site and decreasing translational motion
Km =
[E][S] / [ES] = Kd
Kcat =
Vmax / Et
Phosphorylation of enzymes causes…
Activation/inactivation and covalent modification of the enzyme
Principles of acids and bases
Acid: any base that can donate a proton
Base: any substance that can accept a proton
Most acids important to us physiologically are weak acids
Weak acids commonly observed in animals
Volatile acid - metabolism; CO2
Non-volatile acid - fixed; H2SO4, phosphoric acid, HCl, lactic acid
Henderson-Hasselbach equation
Calculates relationship between an acid’s pKa and the [A-] and [HA] at a given pH
Buffers can only be used reliably within a pH unit of their pKa
pH = pKa + log ([A-]/[HA])
Sources of weak acids and bases in animals
Blood - carbonic acid and bicarbonate, plasma protein buffering
Lungs - CO2 and H2O to carbonic acid to H+ and bicarbonate
Weak acids - aspartic acid, glutamic acid
Weak bases - arginine, histidine, lysine
Major tissue types
Connective
Epithelial
Muscle
Nervous
Basic cell types
Germ
Muscle
Fat
Bone
Blood
Nerve
Epithelial
Immune
Hollow organs
Organs with cavities for liquids and other materials to move through
Smooth muscle, vasculature, more surface area, nerves, and secretory epithelia
(Ex: stomach, intestines, bladder, etc.)
Solid/planar organs
Dense with firm tissue texture and do not have cavities
Nerves, epithelium, muscle, adipocytes, blood supply, connective tissue
(Ex: kidney, liver, pancreas, breast, lung, etc.)
Relate cellular and molecular events to the manifestation of diseases
Mitosis: non-heritable mutations
Meiosis: heritable mutations
Changes in DNA sequence can alter proteins
Mutation types: missense, nonsense, frameshift, insertion/deletion of AA, deletion/insertion of large piece of DNA, repeated segments, single-nucleotide polymorphism (SNP)
Retrogenes: DNA copy of mRNA inserted somewhere new
Different patterns of inheritance
Autosomal dominant
Semi-dominant/co-dominant/additive
Autosomal recessive
X-linked
X-inactivation
Complex mode of inheritance
Loss or gain of function mutations
Epistasis
When is genetic testing appropriate?
To manage inherited diseases
Want to know how much more likely the animal is to get the disease if they carry the risk allele
Uses and limitations of PCR based testing
Used to determine specific genotype of animals, can be used to detect DNA of pathogens in samples from potentially infected animals
Extremely specific, do not test for all possible mutations in a gene or other genes
Uses and limitations of DNA testing
Breed-specific, only test for specific mutation that has been identified, NOT all possible mutations that could cause a similar disease
Mutation tests are ideal, checks for presence of mutated copy of gene
Marker tests have greater error rate, tests for a marker that is found to be inherited along with the disease phenotype
Steps involved in working through a clinical case
Signalment - name, age, sex, neuter status, breed
Presenting complaint(s)
History - recent and past pertinent
Physical examination
Problem list
Differential diagnoses
Plan
DAMNITV scheme
Degenerative
Anomalous (congenital)
Metabolic
Neoplastic, nutritional
Inflammatory, infectious, immune-mediated, iatrogenic, idiopathic, inherited
Trauma, toxins
Vascular
Purpose of cell cycle and regulation
Accurate duplication of DNA and segregation of copies into 2 daughter cells, duration in each part of the cycle varies by cell type
S phase (synthesis), G2 (gap), M phase (mitosis), G1, G0 (quiescent)
Controlled by cyclin dependent kinases (Cdk) that phosphorylate proteins/prevent major cell cycle events and are regulated by cyclin
Structural and functional relationships within the nucleus
Nuclear envelope: lipid bilayer, separate cytoplasm from nucleus
Chromatin: euchromatin (uncoiled, relaxed) and heterochromatin (bound, dense)
Rough ER: captures select proteins from cytosol, covered in ribosomes (further processing, post-translational modifications)
Components and functions of the nucleolus
Not membrane bound, site of rRNA transcription, processing and ribosomal assembly
-Dense tubular component: nascent RNA (transcription)
-Granular component: site of assembly of pre-ribosomal subunits
-Fibrillar center: rRNA genes, RNA polymerase, signal recognition particle (SRP)
G1-Cdk complex
Cyclin D
Cdk4, Cdk6
G1/S-Cdk complex
cyclin E
Cdk2
S-Cdk complex
cyclin A
Cdk2
M-Cdk complex
cyclin B
Cdk1
Transport of proteins into the nucleus depends on
a. protein size
b. nucleoporins
c. nuclear export signal, importin a/b, Ran-GTP
d. nuclear export signal
a. protein size
In the nucleolus, the fibril center contains
a. RNA polymerase, newly made rRNA
b. rRNA genes, RNA polymerase, pre-ribosomal subunits
c. newly made rRNA
a. RNA polymerase, newly made rRNA
The cell cycle is controlled by
a. internal and external factors
b. internal and external cues altering cyclin dependent kinase activity
c. time only
d. tumor suppressor genes
b. internal and external cues altering cyclin dependent kinase activity
Phosphorylation of Rb occurs by ___ and allows for ___.
a. Cdk4-cyclin D complex, transition into M phase
b. Cdk4-cyclin D complex, progression through checkpoint 1
c. Cyclin D, transition into S phase
d. Cdk2, transition into S phase
b. Cdk4-cyclin D complex, progression through checkpoint 1
Pelger-Huet anomaly resulting in hypomorphic nuclei in granulocytes is due to
a. mutations in p53
b. mutations in various tumor suppressor genes
c. Rb inactivation
d. mutations in lamins
d. mutations in lamins
Relationship between plasma membrane and membrane bound intracellular organelles
Membrane systems form enclosed compartments separate from the cytosolic compartment
Creates functionally specialized aqueous spaces within the cell that allow for biochemical reactions requiring very different conditions to occur
Membrane contains proteins to import/export specific metabolites
How proteins move through the rough endoplasmic reticulum and Golgi
SRP binds to ribosome to stop growth of protein, ribosome attaches to ER
Traffic from ER to the Golgi is regulated by vesicle coating with COP II, transit through the Golgi is regulated by COP I
Organization and function of the rough endoplasmic reticulum
Consists of stacks of flattened cisternae interconnected by portions of tubular rough ER surrounded by cytosol
Ribosomes present in linear array attached to membranes
Lumen or cisterna contains glycosylated polypeptides