Lecture Quiz 2

Question 1

What is sphingosine

Answer 1

polar/hydrophillic phospholipid

Question 2

Describe phospholipids

Answer 2

water solubule heads and water insoluble tails

separate the cytoplasm of a cell from the outside world

Question 3

Describe the plasma membrane

Answer 3

double layer of phospholipids

cholesterol and protein embedded in it

Question 4

What does cholesterol do in the plasma membrane?

Answer 4

decreases membrane fluidity

Question 5

What do proteins do in the plasma membrane?

Answer 5

serve as recognition, receptor, and transport proteins

Question 6

What are the functions of the plasma membrane?

Answer 6

isolate the cell from the external environment
regulate the exchange of essential compounds
communicate with the environment

Question 7

Define gradient

Answer 7

a difference of concentrations between two regions in space

Question 8

What is passive transport?

Answer 8

the movement of molecules from high concentration to low concentration
down the gradient

Question 9

What is active transport?

Answer 9

the movement of molecules from low to high concentration
against the gradient
this process requires energy

Question 10

What is diffusion?

Answer 10

movement of molecules down the concentration gradient - from high concentration to low concentration

Question 11

Define simple diffusion

Answer 11

small water-soluble molecules and fat-soluble molecules can directly diffuse through the phospholipid bilayer down the concentration gradient, from high to low

Question 12

Define facilitated diffusion

Answer 12

Ions and bigger water-soluble molecules, such as amino acids and monosaccharides, can diffuse through the membrane with the help of transport proteins

Question 13

What do channel proteins do?

Answer 13

pores
form permanent hydrophilic opening
ions go through pores down the concentration gradient

Question 14

Permeability of channels is often regulated by what two things?

Answer 14

Chemicals (ligands) or voltage

Question 15

What do carrier proteins do?

Answer 15

bind to specific molecule

changes the shape of the carrier in such a way that the molecule is passed through the other side of the plasmamembrane

Question 16

What are aquaporins?

Answer 16

special channels for water molecules to pass through the plasma membrane directly

Question 17

What is osmosis?

Answer 17

The movement of water down the concentration gradient into a cell

Question 18

Define isotonic

Answer 18

when water concentration in the solution is the same as inside the cell, and the movement of water into the cell and out of the cell is the same

Question 19

Define hypotonic

Answer 19

when the concentration of water in the solution is higher than in the cell
concentration of other substances (ions) is lower than in the cell
water enters the cell, increasing its volume

Question 20

Define hypertonic

Answer 20

when the concentration of water in the solution is lower than in the cell
concentration of other substances (ions) higher than in the cell
Water leaves the cell and the cell shrinks

Question 21

Describe active transport

Answer 21

substances are moved against their concentration gradient which requires energy input
primary active transport - pumps, energy comes from ATP
secondary active transport - symport or antiport, energy comes from diffusion of another substance

Question 22

What is endocytosis?

Answer 22

the cell engulfs materials and forms vesicles that separate the from the cell membrane and float in the cytoplasm

Question 23

What are the three types of endocytosis?

Answer 23

pinocytosis
phagocytosis
receptor-mediated endocytosis

Question 24

What cellular processes involve exocytosis?

Answer 24

secretion of proteins like enzymes, peptide hormones, and antibodies from cells
turnover of plasma membrane
release of neurotransmitter from presynaptic neurons
placement of membrane proteins
antigen presentation during the immune response
recycling of plasma membrane-bound receptors

Question 25

What is vesicular trafficking?

Answer 25

moves substances within the cell from one membrane-enclosed area of the cell or organelle to another

Question 26

What is transcytosis?

Answer 26

moves vesicles into the cell, through, then out of it endothelialiocytes lining the capillary enterocytes lining the gut

Question 27

What are the four types of tissue?

Answer 27

Epithelial connective muscle nervous

Question 28

What is a tight junction?

Answer 28

a type of cell junction | a fluid that seal that prevents fluid from leaving a cavity

Question 29

What is an anchoring junction?

Answer 29

cell junction adhesion found in tissues that stretch, such as a heart muscle

Question 30

What is a gap junction?

Answer 30

cell junction | allows a passage of chemical and electrical signals

Question 31

What are the properties of epithelial tissue?

Answer 31

cells bound tightly together in sheets apical and basal surfaces cells rest on basement membrane capable of rapid cell division

Question 32

What can epithelial tissues be subdivided into?

Answer 32

glandular (secretory) and surface epithelium

Question 33

All epithelia are named according to:

Answer 33

number of cell layers cell shapes surface modifications

Question 34

What are the two names for different number of cell layers in epithelia?

Answer 34

simple - single layer of cells resting on basal membrane | stratified - multiple layers of cells

Question 35

What are the three different cell types in epithelia?

Answer 35

squamous - flattened or scale-like cuboidal - resembles a cube columnar - cylindrical in shape

Question 36

Describe simple squamous epithelia

Answer 36

form the thinnest membranes in the body | it is found in the sacs in lungs and lining of blood vessels

Question 37

Describe simple cuboidal epithelia

Answer 37

found lining ducts and other tubular structures often adapted for secretion and absorption kidney tubules and pancreatic ducts are made of this tissue

Question 38

Describe simple columnar epithelia

Answer 38

cells are taller than they are wide most commonly found lining the digestive tract and some exocrine glands functions to absorb nutrients and secrete mucous may be equipped with cilia or microvilli

Question 39

Describe pseudostratified columnar epithelium

Answer 39

found lining the trachea and bronchi, as well as certain areas of the naval cavity often ciliated to facilitate mucus removal from the airway

Question 40

Describe stratified squamous epithelium

Answer 40

designed for abrasion and other abuse protects against absorption, drying out, and infection keratinized stratified squamous epithelium is found in the epidermis of the skin upper layers formed by dead cells filled with waterproof keratin nonkeratinized stratified squamous epithelium is the mucous membrane which lines most body orifices

Question 41

Describe stratified cuboidal and columnar epithelia

Answer 41

found in mammary glands and salivary glands | adapted for secretion and absorption of water

Question 42

Describe transitional epithelium

Answer 42

capable of a great deal of distension when stretched it appears as stratified squamous found in the lining of the urinary bladder, urethra, and ureters

Question 43

Define glands

Answer 43

one or more cells that makes and secretes an aqueous fluid: mucus, hormones, enzymes, etc formed by modified epithelial tissue classified by site of product release

Question 44

Describe endocrine glands

Answer 44

have no ducts release their secretory products into the interstitial spaces around the cells hormones diffuse into nearby capillaries and are then carried to all parts of the body

Question 45

Describe exocrine glands

Answer 45

more numerous than endocrine glands secrete their products onto body surfaces or into body cavities have a secretory part and a duct ex: mucous, sweat, oil, or salivary glands classified according to shape and structure of the duct or mode of the secretion

Question 46

What is the merocrine mode of secretion?

Answer 46

secretory vesicles are moved to the apical surface where the vesicles coalesce with the membrane on the apical surface to release the product

Question 47

What is the apocrine mode of secretion?

Answer 47

apical portions of cells are pinched off and lost during the secretory process mammary glands release their products in this manner

Question 48

What is the holocrine mode of secretion?

Answer 48

involves death of the cell | sebaceous glands release their product in this manner