Ek Lecture 4 - The Eukaryotic Cell

Front 1

nucleus

Back 1

contains all of the DNA in an animal cell

Front 2

nuclear envelope/membrane

Back 2

double phospholipid layer that surrounds nucleus

Front 3

nuclear pores

Back 3

holes that perforate the nuclear membrane

Hint 3

RNA can get out through them, but DNA cannot

Front 4

nucleolus

Back 4

place within the nucleus where rRNA is transcribed and the ribosome subunits are assembled

Front 5

endocytosis

Back 5

the way that cells acquire substances from external environment

Hint 5

phagocytosis, pinocytosis, receptor mediated endocytosis

Front 6

exocytosis

Back 6

release of substances from cell to external environment

Front 7

endoplasmic reticulum

Back 7

membranous walls that separate cytosol from ER lumen

Front 8

cytosol

Back 8

liquid found inside cells; contains organelles

Front 9

ER lumen/cisternal space

Back 9

the extracellular side of the ER

Front 10

granular/rough ER

Back 10

ER near the nucleus that contains ribosomes

Hint 10

proteins created here go into the ER lumen toward the Golgi

Front 11

Golgi apparatus

Back 11

series of flattened membrane bound sacs that organizes, changes and concentrates the proteins

Hint 11

proteins not possessing a signal sequence are expelled from the cell

Front 12

secretory vesicles

Back 12

protein filled vesicles that are released from the Golgi to mature into lysosomes

Hint 12

vehicle that supplies cell membrane with its integral proteins and lipids; also membrane expansion

Front 13

lysosomes

Back 13

fuse with endocytotic vesicles and contain enzymes to break down every major type of macromolecule

Hint 13

also degrade cytosolic proteins

Front 14

agranular/smooth ER

Back 14

lacks ribosomes
shares in cholesterol formation and conversion to steroids
synthesizes phospholipids
oxidizes foreign substances, detoxifies drugs, pesticides, etc

Hint 14

triglycerides are produced here and stored in fat droplets

Front 15

adipocytes

Back 15

cells containing fat droplets

Hint 15

important in energy storage and body temperature regulation

Front 16

peroxisomes

Back 16

cytosolic vesicles that grow by incorporating lipids and proteins from the cytosol
inactivate toxic substances
regulate oxygen concentration
role in synthesis and breakdown of lipids
metabolism of nitrogenous bases and carbohydrates

Hint 16

production and breakdown of H2O2

Front 17

cytoskeleton

Back 17

network of filaments that determines the structure and motility of a cell

Hint 17

contains microtubules and microfilaments

Front 18

microtubules

Back 18

rigid hollow tubes made from a protein called tubulin

Hint 18

used in flagella and cilia
used to make the mitotic spindle

Front 19

microfilaments

Back 19

made of protein called actin
contractile force in microvilli and muscle

Hint 19

squeeze membrane together in phagocytosis and cytokinesis

Front 20

axoneme

Back 20

major portion of flagella and cilia that contains microtubules in 9+2 arrangement

Front 21

flagella

Back 21

found in sperm

Hint 21

made from microtubules

Front 22

cilia

Back 22

only found in fallopian tubes and respiratory tract

Hint 22

made from microtubules

Front 23

dynein

Back 23

protein that creates the cross bridges that connect the outer pairs of microtubules to their neighbors

Front 24

centrosome

Back 24

microtubule organizing center

Front 25

centrioles

Back 25

function in production of flagella and cilia

Front 26

actin

Back 26

protein that forms microfilaments

Front 27

cytoplasmic streaming

Back 27

flowing of cytoplasm in eukaryotic cells

Front 28

tight junctions

Back 28

watertight seal from cell to cell that blocks ions, water and other molecules from moving around and past cells

Hint 28

found in epithelial tissue in organs like the bladder, the intestines and the kidney

Front 29

desmosomes

Back 29

join two cells at a single point on the cytoskeleton

Hint 29

found in tissues that experience a lot of stress like skin or intestinal epithelium

Front 30

gap junctions

Back 30

small tunnels connecting cells that allows small molecules and ions to move around

Hint 30

in cardiac muscle, allow for the action potential to spread from cell to cell

Front 31

mitochondria

Back 31

energy powerhouses of the cell

Hint 31

home of the Krebs Cycle
have some of their own DNA that replicates independently from rest in the cell

Front 32

endosymbiont theory

Back 32

mitochondria may have evolved from a symbiotic relationship between ancient prokaryotes and eukaryotes

Front 33

inner membrane

Back 33

inner part of phospholipid bilayer of mitochondria

Hint 33

holds the electron transport chain

Front 34

cristae

Back 34

infolding of the inner mitochondrial inner membrane that houses the electron transport chain and the enzyme catalyzing the synthesis of ATP

Hint 34

mitochondrial matrix

Front 35

outer membrane

Back 35

outer part of phospholipid bilayer of mitochondria

Front 36

intermembrane space

Back 36

space between inner and outer membrane
home of oxidative phosphorylation

Front 37

epithelial tissue

Back 37

sheets of tightly packed cells that line organs and body cavities

Hint 37

separates free body surfaces from their surroundings

Front 38

connective tissue

Back 38

animal tissue that functions mainly to find and support other tissues, having a sparse population of cells scattered through an extracellular matrix

Hint 38

blood, lymph, bone, cartilage

Front 39

neuronal communication

Back 39

rapid, direct and specific form of communication

Front 40

hormonal communication

Back 40

slower, spread throughout the body, affects many cells and tissues differently

Front 41

interstitial fluid

Back 41

fluid between cells

Front 42

paracrine signalling/system

Back 42

type of system in which the target is near the signal releasing cell

Hint 42

uses local mediators to pass signals

Front 43

neuron

Back 43

highly specialized cell capable of transmitting an electrical signal from one cell to another via electrical or chemical means
basic anatomy: dendrites, cell body, axon

Hint 43

depends almost entirely on glucose and the efficiency of aerobic respiration for its chemical energy

Front 44

dendrites

Back 44

short, highly branches processes of a neuron that convey nerves impulses toward the cell body

Front 45

axon hillock

Back 45

the conical region of a neuron's axon where it joins the cell body
region where nerve signals/action potentials are generated

Front 46

axon

Back 46

a typically long extension from a neuron that carries nerve impulses away from the cell body toward target cells

Front 47

action potential

Back 47

a rapid change in membrane potential of an excitable cell caused by stimulus triggered, selective opening and closing of voltage sensitive gate in sodium and potassium ion channels

Front 48

resting potential

Back 48

the membrane potential characteristic of a nonconducting excitable cell with the inside of the cell more negative than the outside

Front 49

voltage gated ion channels

Back 49

a specialized ion channel that opens or closes in response to a change in membrane potential

Hint 49

sodium and potassium are the most important ones

Front 50

depolarization

Back 50

an electrical state in an excitable cell in which the inside of the cell becomes less negative with regard to the outside of the cell at the resting membrane potential

Front 51

repolarization

Back 51

when sodium ions start flowing out of the cell making the inner membrane of the cell more negative than the outside

Front 52

hyperpolarization

Back 52

when the inside of the membrane becomes even more negative than it is at resting potential

Front 53

threshold stimulus

Back 53

the potential that must be reached for an action potential to be initiated

Front 54

synapse

Back 54

connection between a synaptic terminal of an axon and a signal receiving (dendrite or cell body) or another neuron of effector cell

Hint 54

can be chemical or electrical

Front 55

electrical synapses

Back 55

composed of gap junctions between cells
bidirectional and transmit signals faster than chemical synapses

Hint 55

very uncommon

Front 56

chemical synapse

Back 56

unidirectional and involve the release of a chemical neurotransmitter by the presynaptic neruron

Front 57

synaptic cleft

Back 57

narrow gap between a synaptic terminal of an axon and a signal receiving (dendrite or cell body) or another neuron of effector cell

Front 58

brownian motion

Back 58

random motion of molecules

Front 59

neurotransmitter

Back 59

chemical messenger released from the synaptic terminal of a neuron at a chemical synapse that diffuses across the synaptic cleft and binds to and stimulates the postsynaptic cell

Front 60

second messenger system

Back 60

a molecule or ion that relays a signal to a cell's interior in response to a signal received by a signal receptor protein

Front 61

myelin

Back 61

insulating coat of cell membrane that is interrupted by nodes of Ranvier

Hint 61

in PNS, produced by Schwann cells
in CNS, produced by oligodendrocytes

Front 62

Schwann cells

Back 62

produces myelin in PNS

Front 63

white matter

Back 63

myelinated axons

Front 64

gray matter

Back 64

neuronal cell bodies

Front 65

nodes of Ranvier

Back 65

gaps between myelin where saltatory conduction takes place

Front 66

saltatory conduction

Back 66

rapid transmission of a nerve impulse along an axon, jumping from one node of Ranvier to another, skipping the myelinated sheaths

Front 67

sensory neurons

Back 67

receives signals from a receptor cell that interacts with its environment and then passes the signal on to other neurons

Hint 67

afferent and located dorsally (toward back) from spinal cord

Front 68

interneurons

Back 68

transfers signals from neuron to neuron

Hint 68

makes up 90% of all neurons in body

Front 69

motor neurons

Back 69

carries signals to a muscle or gland called the effector

Hint 69

efferent and located ventrally (toward front/abdomen) from spinal cord

Front 70

effector

Back 70

muscle or gland that performs the body's response to stimuli

Front 71

nerves

Back 71

bundle of axons and dendrites tightly wrapped in connective tissue

Front 72

central nervous system (CNS)

Back 72

function is to integrate nervous signals between sensory and motor neurons

Hint 72

brain and spinal cord

Front 73

peripheral nervous system (PNS)

Back 73

handles the sensory and motor functions of the nervous system

Hint 73

everything other than brain and spinal cord

Front 74

somatic nervous system

Back 74

designed primarily to respond to the external environment

Hint 74

contains sensory and motor functions

Front 75

autonomic nervous system

Back 75

motor portion conducts signals to smooth muscle, cardiac muscle and glands

Hint 75

function is generally involuntary

Front 76

sympathetic

Back 76

fight or flight

Front 77

parasympathetic

Back 77

rest and digest

Front 78

acetylcholine

Back 78

neurotransmitter used by all preganglionic neurons in the ANS and by the postganglionic neurons in the parasympathetic system

Front 79

(nor)epinephrine

Back 79

neurotransmitter used by the postganglionic neurons in the sympathetic nervous system

Front 80

cornea

Back 80

transparent frontal part of the sclera which admits light into the vertebrate eye

Front 81

lens

Back 81

the structure in the eye that focuses light rays onto the retina

Front 82

ciliary muscle

Back 82

contracts and bring focal point closer to lens (more spherical)
relaxes and focal distance increases from lens (flattens)

Hint 82

attached to ligaments on the lens

Front 83

retina

Back 83

innermost layer of the vertebrate eye, containing rods and cones and neurons

Front 84

rods

Back 84

photoreceptor sensitive to black and white and enables night vision

Front 85

cones

Back 85

photoreceptor that detects color during the day

Front 86

iris

Back 86

regulates diameter of pupil and the amount of light entering the vitreous chamber

Front 87

pupil

Back 87

opening in the colored portion of the eye called the iris

Front 88

outer ear

Back 88

skin or cartilage commonly referred to as the ear

Front 89

middle ear

Back 89

tympanic membrane, malleus, incus, stapes

Front 90

inner ear

Back 90

cochlea, hair cells of the Organ of Corti, semicircular canals