AN SC 420 Quiz 2
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AN SC 420 Quiz 2
AN SC 420
Quiz 2 study cards
What are the 3 distinguishing features of collagen?
Right-handed triple helical domain
Glycine is every 3rd AA in helix
What are the primary, secondary, and tertiary structures of collagen?
R-handed super triple helix
What is the AA pattern in the primary structure of collagen?
What causes coiling in the secondary collagen structures?
Steric repulsion btwn Pro at X position and Hyp at Y
Hyp stabilizes helix
What forms "ghosts" in collagen?
What type of collagen is in rat tail tendon?
What is the structure of proteoglycans?
Glycosaminoglycan sub branches (leaves)
Recurring disaccharide units
What are the 3 glycosaminoglycans in a collagen proteoglycan?
What do network collagens form and what do they regulate?
Loose tetrameric structures; skeleton of basement mem collagen
Cell adhesion and migration
What type(s) of collagen are in the epimysium?
What type(s) of collagen are in the perimysium?
Type 1, 3, 5
What type(s) of collagen are in the endomysium?
Type 1, 3, 4, 5
What types of collagen are in cartilage?
2, 9, 11
What types of collagen are in skeletal muscle?
1, 3, 4, 5
What types of collagen are in basement mem?
4, 6, 13, 15, 18, 19
What types of collagen are in
What types of collagen are in tendon?
1, 3, 5
What types of collagen are in cornea?
1, 5, 8
What types of collagen are in skin?
What is the process of cross linking in collagen?
Allysines bind to hydroxyallysines = aldimines
Aldimines reconfigure into keto-amines
Keto-amines re-arrange into cross-links = mature
What are 2 mature (trivalent) cross-links?
What are the 7 muscle shapes?
Why is red meat red?
High in myoglobin
High in hemoglobin
Dense capillary bed
Why is white meat white?
Relies on incomplete oxidation of glycogen
What are 2 factors affecting muscle physiological behaviour?
Speed - fast/slow
Fatigue - tonic/phasic
What determines the speed of muscles?
Myosin isoforms due to light chain differences
What are the 3 muscle fiber types?
Type I - slow oxidative (red)
Type IIA - fast oxidative & glycolytic (intermediate)
Type IIB - fast glycolytic (white)
What are the characteristics of slow muscle fibers (Type I)?
dense cap bed
most mitochondria & lipid
increased protein turnover
smaller than fast
What are the characteristics of fast oxidative/glycolytic muscle fibers (Type IIA)?
recruited after slow ox (Type I)
What are the characteristics of fast glycolytic muscle fibers (Type IIB)?
well organized SR
^ATP & creatine phosphate
more connective tissue
What are the different stains for key enzs?
NADH tetrazolium reductase (red)
Succinate dehydrogenase (red)
What determines muscle fibre type?
Low freq AP - red
High freq AP - white
What does grain-feeding increase?
Fat & cholesterol
What does pasture-feeding increase/decrease?
Increases linolenic acid
Decreases linoleic acid
Increases poly-unsat FAs
How does grain feeding affect carcass quality?
Firmer when cooled
Reduced rate of oxidation/rancidity
How does pasture feeding affect carcass quality?
Softer when cooled
Decreased shelf-stability/increased oxidation & rancidity unless Vit E in feed
What are the 3 flavour/tenderness evaluation techniques?
Consumer sensory panel
Trained sensory panel
Warner-Bratzler Shear force
How does Vitamin D
Increases muscle Ca so increases calpain activity (proteolytic enz)
How do implants affect toughness?
Estrogen leads to cessation of bones
Leads to mature rather than youthful grade
What are the affects of beta-adrenergic agonists?
Increase carcass protein deposition
Reduce subcue fat
Most muscle hypertrophy
Does not affect marbling
What is the dressing process for slaughtered cattle and pigs?
Head removed & inspected
Feet or toenails removed
Tail removed (cattle)
Carcass to gambrel
Hide removed (cattle)
Mamm gland/testes removed
Hot water washed
How are animals other than mature cattle, pig, bird, or goat "dressed"?
Remove head, skin, mamm glands
Remove feet at carpel/tarsal joints
Split (except sheep, calf, rabbit)
How are pigs & goats "dressed"?
Remove hair, toenails, mamm glands
What are the specified risk materials?
- trigeminal ganglia
- spinal cord
- dorsal root ganglia
- Distal ileum + 200 cm proximal (Peyer's patches)
How can UTM cattle be verified using dentition?
They will not have the 3rd permanent incisor
15 month - will have full set of 8 temp teeth
Cook pork at 58.5C for at least 10min
Freeze at -20C for at least 3d
What is the life cycle of
Larvae encyst in pig muscle (red meat)
Human eats infected meat
Digestive juices break down larval capsule
Mature to adult, lay eggs
Travel to muscle/heart/brain
Encyst in tissue
Cause issues (muscle-bad flu, heart-arrhythmia, brain-stroke)
How long must SRM removal records be kept?
Takes 10 years to get BSE-free status
What lymph nodes are inspected PM in the skull?
Retropharyngeal (at back near nasal cavity)
Parotid (sides of head)
Submaxillary (under tongue)
What lymph nodes are inspected PM in the lungs?
Mediastinal (middle of lung)
Open trachea & look for abnormalities
Why are the Masseter (cheek) muscles sliced open and inspected?
(Taenia saginata in humans)
Forms visible cysts