LABS 1&2 (diffusion, cell biology)

Question 1

3 basic parts of cells

Answer 1

1. plasma membrane
2. cytoplasm
3. nucleus

Question 2

plasma membrane

Answer 2

• the outer boundary of the cell
• a dynamic, fluid structure, and selectively permeable membrane
• composed of a phospholipid bilayer thats composed of nonpolar fatty acid tails that are hydrophobic and polar phosphate heads that are hydrophilic.
• integral proteins, peripheral proteins, cholesterol, glycoproteins, glycolipids, and microvilli

Question 3

integral proteins

Answer 3

proteins in the phospholipid bilayer that span the width of the membrane (they go thorugh it from one side to the other)

Question 4

peripheral proteins

Answer 4

proteins of the phospholipid bilayer that are located on only one face/side of the phospholipid bilayer.

Question 5

cholesterol

Answer 5

a steroid that stabilizes the membrane’s structure in the face of changing temperatures.

Question 6

glycolipids & glycoproteins

Answer 6

function in cell recognition

Question 7

microvilli

Answer 7

when the body requires rapid absorption, the plasma membrane folds into projections called microvilli, which increase surface area.

Question 8

cytoplasm

Answer 8

the material inside the cell. consists of 3 parts:

1. cytosol
2. cytoskeleton
3. organelles

Question 9

cytosol

Answer 9

• the fluid portion of the cytoplasm

- contains water, solutes, RNA enzymes, & other proteins

Question 10

cytoskeleton

Answer 10

a collection of protein filaments including actin filaments, intermediate filaments, and microtubules.

Question 11

actin filaments

Answer 11

• small filaments
• mostly located along plasma membrane and in the core of microvilli.
• help maintain the shape of the cell and fxn in cell movement.

Question 12

intermediate filaments

Answer 12

• medium filaments
• rope-like structures that help maintain shape of organelles and the nucleus
• give the cell mechanical strength

Question 13

microtubules

Answer 13

• largest filaments
• hollow tubes that maintain shape of cell
• hold organelles in place
• move substances within cell
• fxn in cell division
• form core of motile extensions from the cell called cilia and flagella

Question 14

cilia

Answer 14

small hair-like extensions that beat rhythmically together to propel substances past the cell.

Question 15

flagella

Answer 15

• single tail-like extensions that propel the cell itself

- sperm are the only flagellated cells in the human body

Question 16

organelles

Answer 16

• specialized cellular compartments that carry out a variety of functions
• 7 types: ribosomes, peroxisomes, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, centrioles

Question 17

ribosomes

Answer 17

• small & granular
• composed of 2 subunits
• 1) some float freely in cytosol
• 2) some are bound to membrane of another organelle (RER) or nucleus
• not enclosed by a membrane
• sites of protein synthesis in the cell
• rib-osomes–> ribs–> protein–> makes protein

Question 18

peroxisomes

Answer 18

• small, round, and vesicular
• contain enzymes that catalyze rxns to detoxify chemicals produced by cellular rxns, metabolize fatty acids, and synthesize certain phospholipids

*perox-isomes–> perox–ide–>chemical–>cleans up chemicals, and breaks down–fatty acids

Question 19

mitochondria

Answer 19

• bean shaped
• produce most of cell’s ATP (energy)
• have double plasma membrane that encloses central space called the MATRIX
• matrix contains enzymes, mitochondrial DNA, and ribosomes.

Question 20

endoplasmic reticulum

Answer 20

• series of membrane-enclosed sacs
• 2 types
  1) rough (RER)–has ribosomes on its surface, modifies proteins made by ribosomes
  2) smooth (SER)–no ribosomes. responsible for lipid synthesis and detoxification rxns.

*ribosomes make surface bumpy like muscles–muscles are changed by protein–the RER modifies protein
smooth ER like “smooth move”–detoxifies body

Question 21

golgi apparatus

Answer 21

• stack of flattened vesicular sacs near RER

- receive vesicles from the RER and other places in the cell and process, modify, and sort the products

Question 22

lysosomes

Answer 22

• vesicular
• filled with digestive enzymes that catalyze rxns that digest particles brought into cell, old and worn-out organelles, and even the cell itself.

*lysosome–>lysol–>breaks down/digests what needs to be cleaned up–>old cell bits

Question 23

centrioles

Answer 23

• paired organelles composed mostly of microtubules located in the central area of cell called CENTROSOME
• organize microtubules
• important in facilitating assembly and disassembly of microtubules

Question 24

Nucleus

Answer 24

• a cell’s biosynthetic center that directs synthesis of nearly all the body’s proteins, and some nucleic acids
• surrounded by a double membrane called the nuclear envelope which has holes called nuclear pores.
• contains chromatin–a ball-like mass of tightly coiled DNA and RNA (ribosomal RNA)
• the birthplace of ribosomes

Question 25

osmosis

Answer 25

movement of water (or a solvent) from a higher concentration of water to a lower concentration of water

or: movement of water/solvent from a lower concentration of solute to a higher concentration of solute.
* H2O–O-Osmosis

Question 26

diffusion

Answer 26

movement of a solute/particles from a higher concentration of particles to a lower concentration of particles

Question 27

tonicity

Answer 27

concentration of solute inside a living cell

1. isotonic
2. hypotonic
3. hypertonic

Question 28

isotonic

Answer 28

• when the extracellular fluid (or other solution) has the same tonicity as the cell.
• no change occurs because they are equal/balanced.

Question 29

hypotonic

Answer 29

• when the extracellular fluid/solution has a lower tonicity than the cell. The the cell pulls the fluid into the cell to “dilute” the cell insides.
• cell can burst=hemolysis

Question 30

hypertonic

Answer 30

• when the extracellular fluid/solution has a higher tonicity than the cell.
• the extracellular fluid pulls the water from the cell to dilute itself which makes the cell shrink/shrivel=crenation

Question 31

passive process

Answer 31

• requires no net input of energy because the energy comes from a concentration gradient.
• diffusion, osmosis, and filtration

Question 32

concentration gradient

Answer 32

a situation where two concentrated areas have different concentrations of solute.

Question 33

filtration

Answer 33

• movement of all through a membrane

- requires pressure

Question 34

what increases the speed of movement?

Answer 34

• gases travel faster than solids
• higher temperature=faster
• smaller particles=faster

Question 35

Brownian movement

Answer 35

• the continuous movement of tiny particles suspended in water
• particles have their own energy that give them the ability to move
• once equally distributed, no more movement