260-269 Flashcards
https://drive.google.com/open?id=0B8uJUY-tie8GZkctcXdsVUZPZUE
https://drive.google.com/open?id=0B8uJUY-tie8GSkpXS2ZJc1hfNnc
insulin
A homopolymer of fructose.
insulin
Highly water soluble.
■ Used to determine glomerular filtration rate (GFR).
Heteropolymer chains containing repeating disaccharide units of an amino
sugar (N-acetylglucosamine, N-acetylgalactosamine) and a uronic acid
(glucaronic acid, iduronic acid).
GLYCOSAMINOGLYCANS (GAGS )
The major structural polysaccharides of extracellular matrix (ECM), connective
tissue (CT), and outer cell membrane surfaces.
GAG
GAG
Because they contain sulfate and carboxyl groups, GAGs are highly negatively
charged and easily attract water, enabling them to cushion their surrounding
structures.
Accumulation of various GAGs (due to enzyme deficiencies) results in
several syndromic diseases.
GAG
https://drive.google.com/open?id=0B8uJUY-tie8GZ3d6bWRQWlZMR2M
https://drive.google.com/open?id=0B8uJUY-tie8GeHlVYUNVek5KclE
https://drive.google.com/open?id=0B8uJUY-tie8GLVg1WUdzS2M5SGc
https://drive.google.com/open?id=0B8uJUY-tie8GeWNKR0lSWm03ckU
PG
Complex carbohydrates that have a central protein molecule to which
many GAGs are attached in a radial (brush-like) pattern.
PG
95% polysaccharide; 5% protein.
■ Linkage of GAGs to the central protein involves a trisaccharide: 2 galactose +
1 xylose.
PG
Central protein is rich in serine and threonine
Located mostly in the ECM.
PG
A homopolymer of b-D-glucopyranose linked by b-1, 4 bonds.
cellulose
Major component of plants.
■ Cannot be digested by humans
cellulose
https://drive.google.com/open?id=0B8uJUY-tie8GZHhEWWRzV2p4OTA
https://drive.google.com/open?id=0B8uJUY-tie8GZHhEWWRzV2p4OTA
A homopolymer of N-acetyl-D-glucosamine linked by b-1, 4 glycosidic
bonds.
■ Major component of insect and crustacean exoskeletons.
chitin
DEXTRAN
A homopolymer of glucose formed by the hydrolysis of sucrose via glucosyl
transferase (dextran sucrase).
■ Produced by Streptococcus mutans.
Sucrose —>Fructose + Glucan (Dextran)
Glucosyl transferase
LEVAN
A homopolymer of fructose formed by the hydrolysis of sucrose via levan
sucrase.
LEvan
Increases adhesion of bacteria to tooth surfaces
LEVAN
Stored intracellularly as reserve nutrients for bacteri
GLYCOPROTEINS
Proteins with covalently linked oligosaccharide (glycan) chains.
GLYCOPROTEINS
Function: Structural components, transport molecules, enzymes, receptors,
and hormones.
GP
Examples: Collagens, proteoglycans, immunoglobulins, selectins, fibronectin,
laminin, thyroid-stimulating hormone (TSH), and alkaline phosphatase.
GLYCOLIPIDS
Sphingolipids with attached carbohydrates
GLYCOLIPIDS
Derived from ceramide
glycolipids
Commonly found on outer cell membrane surfaces, especially in brain
and other nervous tissues.
glycolipid
Examples: Gangliosides, galactosylceramide, and glucosylceramide
saliva
A hypotonic fluid with an average pH ranging from 6 to 7.
saliva
Salivary duct cells reabsorb Na+/Cl− in exchange for K+/HCO3
−.
saliva
Contains mostly water, electrolytes, and organic factors.
Elevated caries risk when salivary flow <——
Elevated caries risk when salivary flow <0.7 mL/min.
https://drive.google.com/open?id=0B8uJUY-tie8GRDRvN1k1clFWaEk
https://drive.google.com/open?id=0B8uJUY-tie8GNUU2RTFaNWtrYm8
Serous (watery) →
contain a-amylase.
Mucous (viscous) →
contain mucins.
https://drive.google.com/open?id=0B8uJUY-tie8GSUxDaWt6RWpOSms
https://drive.google.com/open?id=0B8uJUY-tie8GMW1EYmJFZy16OVk
SALIVARY CONTROL
Controlled by the autonomic nervous system.
Parasympathetic action → serous secretions
Salivary control
Sympathetic action → mucous secret
sal. secr.
Consist of chains of amino acids (polypeptides), which are arranged in specific
three-dimensional conformations.
proteins
Building blocks of polypeptides.
■ Basic structure consists of a central a-carbon atom surrounded by four
groups: a hydrogen atom, carboxyl group, amino group, and an R-group
specific to each amino acid.
AA
All amino acids found in proteins are stereoisomers in the –configuration.
All amino acids found in proteins are stereoisomers in the L-configuration.
Amino acids are covalently linked by peptide bonds at their amino ((x)
and carboxyl (y) groups
Amino acids are covalently linked by peptide bonds at their amino (Nterminus)
and carboxyl (C-terminus) groups
peptide bond
Generally short, polar, and allow the a-carbon to rotate freely about its
axis (Proline has a restricted a-carbon rotation due to its 3° amine).
Generally a trans (not cis) bond
PEPTIDE BONDS
peptide bond
Very stable; generally require proteolytic enzymes to break them.
■ Do not ionize at physiologic pH.
https://drive.google.com/open?id=0B8uJUY-tie8Gb0VRdS1adHJSN00
https://drive.google.com/open?id=0B8uJUY-tie8GVE93Y2VXSjhOVUk
https://drive.google.com/open?id=0B8uJUY-tie8GemRVT3RHNnR3R28
https://drive.google.com/open?id=0B8uJUY-tie8GSTkzTl8yUXdlVzg
disulfide bond
■ Strong, covalent bonds between thiol (–SH) group of two cysteine residues
that stabilizes structure of proteins and prevent denaturation.
DISULFIDE BONDS
Abundant in insulin and Ig.
classification
By R-group. (See Table 6–2.)
■ By dietary necessity. (See Table 6–3.)
■ By metabolic end product. (See Table 6–4.)
https://drive.google.com/open?id=0B8uJUY-tie8GbTM3cW01azJ1ZG8
https://drive.google.com/open?id=0B8uJUY-tie8GazV0dGM2cUxSdGs
https://drive.google.com/open?id=0B8uJUY-tie8GYXNla05fUW9BcXc
https://drive.google.com/open?id=0B8uJUY-tie8GRWxEbVVfUjZFVzA
https://drive.google.com/open?id=0B8uJUY-tie8Geld6eDdKMnh0UkE
https://drive.google.com/open?id=0B8uJUY-tie8GbVdWZ0k5ME1uazg
Primary structure of AA
Primary structure: The specific sequence of amino acids in a polypeptide
chain. Each amino acid in the polypeptide chain is called a residue.
Secondary structure:
The folding of portions of a polypeptide chain.
a-Helix:
Coiled configuration.
■ b-Pleated sheet: ■
Zigzag or pleated configuration.
b-Turn:
Reverse turns that link two sides of a b-pleated shee
Tertiary structure:
The overall three-dimensional conformation of a
polypeptide. Each portion of the polypeptide that can perform a biochemical
or physical function is called a domain.
Quarternary structure:
The spatial arrangement of two or more polypeptide
chains. Each polypeptide is known as a subunit. Associated via noncovalent
interactions.
1/3 of body’s protein.
■
collagen
collagen
Consists of three polypeptide a-chains wound around one another to form
a triple helix
■ Produced by many cells: fibroblasts, epithelial cells, odontoblasts, osteoblasts,
and chondrocytes
collagen
It is the organic matrix in dentin and cementum
collagen
https://drive.google.com/open?id=0B8uJUY-tie8GSFRTRjJwUTFCVmM
https://drive.google.com/open?id=0B8uJUY-tie8GdkVPYkZpeGZPLXM
COLLAGEN
35% glycine; 21% proline; 11% alanine
collagne
Fibers have high tensile strength
rER:
Synthesis of a-chains with glycine-x-y sequence
rER:
Hydroxylation of proline and lysine residues, forming hydroxyproline
and hydroxylysine. Requires vitamin C.
Golgi:
Glycosylation of α-chains, forming procollagen, a triple helix
containing N- and C-terminal propeptides.
Endopeptidases cleave the—– and — terminal propeptides of —–
forming ——
Endopeptidases cleave the N- and C-terminal propeptides of procollagen,
forming tropocollagen
Cross-linking of —– molecules, forming —– fibrils.
Requires —– of lysine via lysine oxidase (contains copper).
Cross-linking of tropocollagen molecules, forming collagen fibrils.
Requires oxidation of lysine via lysine oxidase (contains copper).
https://drive.google.com/open?id=0B8uJUY-tie8GekFDYmVVVmlaTXM
https://drive.google.com/open?id=0B8uJUY-tie8GSW4xWlhhS1ZuRlk
elastin
Fibers are extremely elastic, “rubber-like.”
■ Found in skin, ligaments, arterial walls.
Synthesis can occur simultaneously with collagen.
elastin
Elastin
Amino acid sequence of the proelastin polypeptide chain is typically
glycine-x-y. Other residues include proline, lysine, alanine, and
hydroxyproline (to a lesser extent).
elastin
■ Endopeptidases cleave the N- and C-terminal propeptides of proelastin,
forming tropoelastin.
■ Cross-linking of tropoelastin molecules via desmosine, forming elastin
fibers. Requires oxidation of lysine via lysine oxidase (contains copper).
plasma protein
Synthesized in the liver (except gamma globulins).
■ Act as buffers to stabilize pH.
https://drive.google.com/open?id=0B8uJUY-tie8GN0VKMVdFaXBEdzg
https://drive.google.com/open?id=0B8uJUY-tie8GQWhzNW5sR3RzYVU
Transports O2 in erythrocytes.
hemoglobin
Each heme reversibly— one molecule of O2 when the iron is in a
——- ferrous (Fe2+) state.
Each heme reversibly binds one molecule of O2 when the iron is in a
reduced ferrous (Fe2+) state.
Heme binds ——) with a greater affinity than O2.
Heme binds carbon monoxide (CO) with a greater affinity than O2.
Hb binds ~15% of the CO2 carried inv—— blood (the majority is
carried by —–
Hb binds ~15% of the CO2 carried in venous blood (the majority is
carried by bicarbonate).
Mutations of a and b subunits result in numerous hemoglobin types.
hemoglobin