113

Question 1

what are fat cells?

Answer 1

AKA adipocytes
-10-30% water, 5-10% protein, 60-90% fat (lipid)
-provides energy, storage, insulation, and hormones

Question 2

what are lipids?

Answer 2

-trace amounts of fatty acids
-energy source, hormone messenger, insulation
-triglycerides (stores energy)
-make up the phospholipid membranes
-steroids: cholesterol

Question 3

what are muscle cells?

Answer 3

-contain 70-80% water, 15-20% protein, 2-10% fat, 1% glycogen
-packed with contractile proteins in myofibrils (actin+myosin)
-functions in movement

Question 4

what are proteins?

Answer 4

-amino acid chain
-classified by structural or reactive (enzymes)
-conjugated protein: attached to another molecule

Question 5

what are carbohydrates?

Answer 5

-classified by amount of sugars: mono, di, poly
-monosaccharides: glucose and ribose
-disaccharides: sucrose, maltose, lactose, galactose
-polysaccharides: glycogen (animals), starch (plants)

Question 6

how many carbons do ribose and glucose have?

Answer 6

ribose-5
glucose-6

Question 7

what is glucose?

Answer 7

-energy formed by glycolysis
-substrate for ribose and glycogen production

Question 8

how do carbohydrates serve as energy sources?

Answer 8

-glucose turns into lactate and ATP
-lactate goes back to liver and produces more glucose
-pyruvate can go into the krebs cycle (occurs in mitochondria) and produces large amount of ATP

Question 9

how does ribose function in RNA and DNA?

Answer 9

when a phosphate attaches it serves as the backbone

Question 10

what are the most abundant ions in animal cells?

Answer 10

sodium, potassium, phosphorous, calcium

Question 11

what does the phospholipid do?

Answer 11

-separate the cytoplasm from the extracellular environment
-regulate the passage of water-soluble molecules (glucose, sodium) in/out of cells
-contains proteins that serve as ion + hormone receptors, and transport proteins
-also made up of cholesterol

Question 12

what are cell adhesion molecules?

Answer 12

-proteins in the membrane that stick together

Question 13

how do membrane structures differ?

Answer 13

-intestinal luminal cells have microvilli
-muscle fibers have neuromuscular junctions
-mitochondria and nuclei have leaky outer membranes

Question 14

what are phospholipids?

Answer 14

-2 hydrophobic tails made up of hydrocarbon chains
-polar, hydrophilic head

Question 15

what does cholesterol do in the cell membrane?

Answer 15

regulate the fluidity

Question 16

what is the difference between integral and peripheral proteins?

Answer 16

integral proteins are embedded in and peripheral proteins attach temporarily

Question 17

what do integral proteins serve as?

Answer 17

hormone receptors- such as B-Agonist

Question 18

what are different types of cell adhesion molecules?

Answer 18

-desmosomes: tightly bind the membranes of adjacent cells together
-tight junctions: restrict the movement of material in the space between adjacent cells
-gap junctions: extend between adjacent cells to allow passage of small molecules or ions

Question 19

what are gap junctions important in?

Answer 19

contraction of cardiac muscle and smooth muscle

Question 20

what do membranes transport?

Answer 20

ions and small, polar molecules

Question 21

what are the different types of transportation in membranes?

Answer 21

-endocytosis: take into the cell
-exocytosis: take out of the cell by membrane-bound vesicles fusing with the membrane

Question 22

what are different types of endocytosis?

Answer 22

-phagocytosis: cell membrane wraps around protein and takes it into the cell
-pinocytosis: membrane takes up small amounts of dissolved particles

Question 23

what is osmosis?

Answer 23

-water passing through the membrane through aquaporins to a region of high concentration of solutes
-requires a selectively permeable membrane

Question 24

what is diffusion?

Answer 24

-the dilution of the solvents by the movement of water

Question 25

what does hypotonic mean?

Answer 25

-the extracellular fluid is low in solutes -results in the cells bursting (hemolysis for red blood cells)

Question 26

what does hypertonic mean?

Answer 26

-the extracellular fluid is high in solutes -results in water diffusing out of the cells, which leads to shrinkage (crenation)

Question 27

what is facilitated diffusion?

Answer 27

-specific carrier proteins transport the matching molecule across the membrane -does not require energy -glucose and amino acids

Question 28

how does glucose transport across membranes in facilitated diffusion?

Answer 28

-insulin stimulates the glucose carrier proteins to move the cytoplasm to the cell membranes -the transporter proteins bind glucose and carry it into the cells

Question 29

what is active transport?

Answer 29

-3 sodium is pumped out of the cell and 2 potassium is pumped inside -this results in a difference across the membrane, which leads to a resting membrane potential

Question 30

what are excitable cells?

Answer 30

nerves that transmit information to other nerves

Question 31

how do nerves and muscle fibers act like an electrical wire?

Answer 31

-nervous system generates an electrical signal which is sent to muscle -they conduct current due to the difference of sodium and potassium across cell membranes

Question 32

what is the basis for resting membrane potential?

Answer 32

-the difference of sodium and potassium -potassium can leak out, but cell membrane is impermeable to sodium -this results in a negative charge inside the cell membrane: -60 mV

Question 33

how can sodium enter the cell?

Answer 33

-through an electrically-gated channel (electricity potential varies across the membrane) -depolarization (making it less neg.) opens the gate of ion channels (becomes 40 mV)

Question 34

what is acetylcholine?

Answer 34

-chemical messenger released by a terminal axon -fuses to muscle membrane and binds to the receptors -these receptors are sodium channels, so sodium floods into the muscle cell

Question 35

what is propagation?

Answer 35

-the spread of depolarization across the muscle surface -results in an action potential which contracts the muscle

Question 36

what are the 3 zones of the cell?

Answer 36

-membrane -nucleus -cytosol

Question 37

what is cytosol?

Answer 37

-the gel-like fluid inside the cell -contains organelles, cytoskeleton, and nucleus -also dissolved/suspended products (glucose, proteins, salt) -allows space for functionality

Question 38

what is the endoplasmic reticulum?

Answer 38

-a membranous network -either smooth or rough -smooth: lipid manufacture and glycogen metabolism -rough: has ribosomes, protein production/folding

Question 39

what is the golgi apparatus?

Answer 39

-comprised of lamellae -encloses secretory material in a membrane vesicle for exocytosis or storage -also receives transport vesicles by the phospholipid membranes fusing together -golgi is fedex, the vesicle is the box

Question 40

what is the mitochondria?

Answer 40

-site of ATP production -contains own DNA, RNA, and ribosomes -capable of replication without cell division -kreb cycle enzymes are in the matrix -not found in red blood cells

Question 41

how does the mitochondria bilayer function?

Answer 41

-outer: allows passage for large molecules -inner: has cristae which increases surface area to produce more metabolic water

Question 42

what are lysosomes?

Answer 42

-from ER and golgi -fuses with cytoplasmic vesicles formed by phagocytosis and degrades the unused material inside without damage -found in all mammal cells (specifically liver and white blood cells) except red blood cells

Question 43

what are peroxisomes?

Answer 43

-degrades toxic substances (lipids or alcohol) -found in liver and kidney

Question 44

what are cytoskeletal elements?

Answer 44

-microtubules: spindle fibers responsible for splitting cells in cell division; assists with molecule transport in neurons -intermediate filaments: between adjacent membranes -microfilaments: determine the shape of the cell and assists with movement, comprises most of the cytoskeleton