1What are the three main zones of the cell?
Membrane, Nucleus, and Cytosol
2What does the cytosol contain?
Organelles, cytoskeleton, and nucleus
3What is the purpose of the cytosol?
Allows space for functionality of the cell
4What is the primary difference between the rough ER and the smooth ER?
The rough ER has ribosomes that are essential for translation
5What is the purpose of the Golgi Apparatus?
Takes in and packages secretory cell products and incoming transport vesicles
6What do Mitochondria contain?
Their own DNA, ribosomes, enzymes, and inner membrane folds
7What are the differences between lysosomes and peroxisomes?
Lysosomes are larger
Lysosomes are larger and primarily responsible for breaking down waste materials and cellular debris, while peroxisomes focus on detoxification by breaking down harmful substances like hydrogen peroxide through oxidation reactions
8What are the three cytoskeletal elements?
Microtubules, intermediate filaments, and microfilaments
9What is the difference between a myofilament and a myofibrial?
A myofibril is a larger structure within a muscle fiber that is made up of many smaller protein filaments called myofilaments
10Where are actin and myosin located?
Muscle cells - actin is in the thin filaments and myosin is in the thick filaments
11What is a sarcomere and what is its importance?
Sarcomere is the functional unit of muscle and spans from one Z-band to another Z-band
12What major proteins are associated with thick filaments?
Myosin molecules
13What major proteins are associated with thin filaments?
Actin, troponins, and tropomyosin
14Where are myofibrils located in the skeletal muscle?
Muscle fiber
15Where are sarcomeres located in the skeletal muscle?
Between two neighboring Z-lines
16Where are A bands located in the skeletal muscle?
Within the sarcomere
17Where are I bands located in the skeletal muscle?
Within the sarcomere
18Where are Z lines located in the skeletal muscle?
Between adjacent sarcomeres
19Which muscle types are striated?
Cardiac and skeletal
20Which muscle types are under voluntary control?
skeletal
21What are the levels of organization of skeletal muscle?
slide 7 (muscle body, fasciculi, fiber, etc.)
22What are the three connective tissues associated with skeletal muscle?
Epimysium, perimysium, and endomysium
23What structures surround the myofibril?
Sarcoplasmic reticulum and sarcolemma
24What are structures associated with a nerve?
Nucleus, axon, and axon terminal
25Where does a motor neuron originate?
Brain and spinal cord
26What is the basic structure of the spinal cord?
Dorsal root contains afferent nerves and the ventral root contains efferent nerves
27What are terminal axons?
The final split of an axon where motor end plates attach to the muscle fiber to send electrical signals
28How many terminal axons can there be from a single motor nerve (axon)?
As many as 1,000 muscle fibers
29What are motor end plates and what is their basic structure (neuromuscular junctions)?
What attaches the terminal axon to the muscle fibers, allowing action potentials to travel down and spark muscle contractions
30Where are motor end plates located in mammalian muscle fibers and how motor end plates are there in a single mammalian muscle fiber?
Typically located near the center of the muscle fiber, which has only one NMJ
31Which proteins are essential for contraction?
Actin, myosin, and calcium
32Where is calcium stored in the skeletal muscle?
Terminal cisternae from the sarcoplastic reticulum
33Where is calcium stored in the cardiac muscle?
Sarcoplastic reticulum
34What causes the release of calcium from the sarcoplasmic reticulum in skeletal muscle?
The depolarization of t-tubules and the terminal cisternae
35How does calcium cause contraction in skeletal muscle?
Calcium floods the sarcoplasm, binding to troponin which activates the actin-myosin ATPase, causing the filaments to contract
36What are the major differences in skeletal, smooth, and cardiac muscle?
They are fairly similar, but cardiac muscle cells are branched and attached end-to-end by intercalated disks
37What membrane structures are present in smooth muscle cells that are not present in skeletal muscle fibers?
Dense bodies attached to their cell membrane
38What structures are present in cardiac muscle cells that are not present in skeletal muscle fibers?
Gap junctions and desmosomes
39Which proteins are essential for contraction in smooth muscle?
Actin and myosin
40Where is calcium stored in smooth muslce?
Circulation
41What are the functions of gap junctions and calcium channels?
Calcium diffuses into the cell to initiate contraction through voltage-gate or ligand-gated channels
42How do calmodulin and smooth muscle kinase cause contraction?
Calcium binds to the calmodulin which activates the kinase and causes contraction by binding phosphates to the myosin
43What structures are present in cardiac muscle cells that are not present in skeletal muscle fibers?
Intercalated discs, which contain gap junctions and desmosomes, and a single central nucleus
44Why do type I muscle fibers produce more energy from fatty acids and ketone bodies than type IIX muscle fibers?
They have abundant mitochondria which uses fatty acids and ketone bodies for energy
45What are the products of carbohydrate, protein, and fat hydrolysis in the small intestine?
Carbohydrates such as glucose, proteins such as amino acids, and fats such as glycerol and fatty acids
46In what organs are chylomicrons and very low-density lipoproteins produced?
Chylomicrons are produced in the small intestines and low-density lipoproteins are produced in the liver
47What is the importance of ATP production by mitochondria from fatty acids and ketone bodies?
During fasting and low glucose availability, mitochondria produce ATP from fatty acids through β-oxidation, generating acetyl-CoA for the Krebs cycle. Ketone bodies, derived from acetyl-CoA, serve as an alternative energy source
48How does the body maintain glucose homeostasis during fasting?
Gluconeogenisis where amino acids are transferred to the liver and converted to glucose