ANSC 2053 lecture 14- intro to muscle composition and contraction

Girka Exam 3

what are the 5 main components of meat?

water, muscle, connective tissue, adipose tissue, bone

the proportion of these components varies by?(4)

species, age, muscle location, cut of meat

basic components of living animal carcasses(5)

muscles, connective tissue, epithelial tissue, nervous tissue, body systems

what does the slaughtering process remove?(5)

blood, viscera, head, hair and skin, organs

what is left after slaughtering?

muscle, bone, fat

what does the proportion of muscle, bone, and fat determine?

quality, leanness, and value of the cut.

what are the 3 types of muscle tissue?

skeletal, cardiac, smooth

what % of skeletal muscle is the carcass weight in meat ?

35-65%

offal definition

edible organs

what are key features of muscle fibers?

contain multiple nuclei, nuclei located at periphery, just under the sarcolemma

why do muscle fibers have multiple nuclei?

it supports the large sarcoplasmic volume

what causes muscle contraction?

Ca2+ release

T/F. muscle fibers are not unique to muscle tissue.

false, they are

in the muscle fiber the sarcomeres are

the smallest functional contractile unit.

due to repeating sarcomeres, myofibrils appear __________

striated

sarcomeres contain 2 types of filaments

thin and thick filaments

muscle contraction occurs when _______ binds to ________

myosin, actin

what is the sliding filament theory?

thin and thick filaments are sliding past each other during contraction, their length is not changing

what two things are needed for muscle contraction?

calcium and ATP

how does myosin and actin interact?

through a cross-bridge cycle

what are the steps in muscle contraction?(5)

1. ATP binding, 2. ATP hydrolysis, 3. actin binding, 4. power stroke, 5. tight binding state

what is the most abundant major connective tissue protein?

collagen

what is connective tissues role?

it is the glue and holds muscle fibers together

T/F. elastin should be trimmed/removed before cooking.

true

adipose tissue=

fat

what color is fat in young animals vs in older animals

it is white in younger animals and becomes more yellow with age

bone weighs less or more than muscle?

more