Collagen and Motor Proteins

extracellular matrix, connective tissue, bone

Collagen is the protein that plays a major structural role in the ______, _______, and in ______

triple

Collagen has a _____ helix structure

Gly

Collagen has unusual amino acid composition with every third residue being ______.

gly-pro-hyp

Each collagen chain consists of repeating triplets, the most common is ______

hydroxyproline

What is the full name of HYP?

vitamin C

______ is required for converting Pro to Hyp

hyp, scurvy

In the absence of vitamin C, Collagen contains too few _____ , resulting in:

• loss of teeth

• poor wound healing

• easy bleedingT

  This disease is called ______

motor proteins

_____________ use the chemical energy of ATP hydrolysis to carry out mechanical work.

ATP hydrolysis

motor proteins use the chemical energy of _____ to carry out mechanical work

actin filaments, microtubules

Motor proteins act on structural elements such as ________ and _____ to generate the movements that allow the cells to reorganize their contents, change their shape, and move.

myosin

______ acts on actin filaments

kinesin

______ acts on microtubule tracks

muscle contractions

Myosin is responsible for ________

intracellular transport

Kinesin is responsible for ______

2, long

myosin has ___ heads and a ______ tail

actin, adenine nucleotide

In Myosin

• each head has a binding site for ______ and ______

ATP hydrolysis, actin filament

_______ drives the physical movement of myosin along an _______ in muscle contraction

actin

Myosin-actin reaction cycle: #1

• Myosin head binds to an ____ subunit of the filament

ATP, dissociates

Myosin-actin reaction cycle: #2

• _____ binding alters the conformation of the myosin head, so it ______ from actin.

ADP + Pi, rotates, inc

Myosin-actin reaction cycle: #3

• Hydrolysis of ATP to _____ triggers a conformational change that _______the myosin and _____ its affinity to actin.

actin, farther

Myosin-actin reaction cycle: #4

• Myosin binds to an ____ subunit ____ along the thin filament.

ADP, Pi, original, move

Myosin-actin reaction cycle: #5

• Release of ____ and _____ returns the myosin to its _____ shape.

• This causes the thin filament (actin) to _____ relative to the thick filament (myosin).

atp, adp

Myosin-actin reaction cycle: #6

• _____ replaces the lost ____ to repeat the cycle.

tubulin, atp

Each head for KINESIN includes a binding site for _____ and a binding site for an _______.

microtubule

Kinesin transports cargo by moving along a _______ track

ATP, swing, forward, pos

Kinesin transport: #1

• _____ binding to the leading head induces a conformational change, causing a _____ of the trailing head _____ by 180 degree toward the ______ end of the microtubule.

tubulin, ADP, forward

Kinesin transport: #2

• The new leading head binds to a _____ subunit and releases its ____ . This step moves kinesin’s cargo _____ along the filament.