Mcat Biology Lecture 4

Front 1

The structure and motility of a cell is determined by a network of filaments known as the ____.

Back 1

cytoskeleton

Front 2

____ is the site of lipid synthesis including steroids. The ____ also helps to ____ some drugs.

Back 2

Smooth ER
Smooth ER
Detoxify

Front 3

____ contain hydrolytic enzymes that digest substances taken in by ____. ____ come from the golgi.

Back 3

Lysosomes
Endocytosis
Lysosomes

Front 4

The ____ modifies and packages proteins for use in other parts of the cell & outside the cell.

Back 4

Golgi

Front 5

____ has ribosomes attached to its cytosol side and it synthesizes virtually all ____ not used in the cytosol. ____ synthesized on the ____ are pushed into the ER lumen and sent to the Golgi.

Back 5

Rough ER
Protein
Protein
Rough ER

Front 6

In order to reach the ____ a substance must cross a membrane via ____ or ____ or ____, but it can reach the ____ via ____ w/o ever transporting across a membrane.

Back 6

Cytosol
Passive diffusion
Factilitated diffusion
Active transport
ER lumen
endocytosis

Front 7

two main "sides" of a cell

Back 7

cytosol
ER lumen

Front 8

The mitotic spindle is made from ____.

Back 8

microtubules

Front 9

____ - larger than microfilaments. They are rigid hollow tubes made from a protein called tubulin.

Back 9

microtubules

Front 10

____ - vesicles in the cytosol involved in the production and breakdown of hydrogen peroxide.

Back 10

peroxisomes

Front 11

agranular or smooth endoplasmic reticulum (ER)

Back 11

lipid synthesis
oxidized foreign substances (detoxifies drugs, toxins, pollutants)

Front 12

Adipocytes -

Back 12

cells containing predominately fat droplets

Front 13

____ - series of flattened membrane bound sacs. Lysosome production, "warehouse" functions - packing, shipping, unpacking.

Back 13

Golgi (apparatus, or complex or body)

Front 14

Granular or rough ER

Back 14

has many ribosomes attached to it on the cytosolic side
protein synthesis

Front 15

____ - the "extracellular fluid" side of the ER

Back 15

ER lumen
cisternal space

Front 16

____ - "bags of stuff" release their contents through exocytosis

Back 16

Secretory vesicles

Front 17

____ - contain enzymes that are capable of breaking down every type of major macromolecule w/in the cell.

Back 17

Lysosomes

Front 18

Cytosol -

Back 18

aqueous solution inside the cell

Front 19

Exocytosis -

Back 19

reverse of endocytosis
exo- = exit
endo- = enter

Front 20

Cells can acquire substances from the extracellular environment through ____.

Back 20

endocytosis

Front 21

____ - to eat
____ - to drink

Back 21

phagocytosis (specific cells, white blood cells)
pinocytosis (#1)

Front 22

Only eukaryotes have ____. Dna cannot leave the ____ therefore transcription must take place in the ____. ____ leaves the ____ through ____.

Back 22

nuclei
nucleus
nucleus
RNA
nucleus
nuclear pores

Front 23

Semicircular canals are located ____ and are responsible for ____.

Back 23

inner ear
balance

Front 24

(3) parts of the ear

Back 24

Outer
middle
inner

Front 25

The ____ of the ____ transduce into neural signals in the ear.

Back 25

hair cells
organ of corti

Front 26

The cochlea detects ____. The semicircular canals detect ____ & ____ of the head.

Back 26

sound
orientation
movement

Front 27

begins the middle ear

Back 27

tympanic membrane (eardrum)

Front 28

flattening the eye by relaxing the ciliary muscles makes the lens ___ powerful. Making the lens ____ powerful moves the focal point ____ from the lens.

Back 28

less
less
away

Front 29

what type of lens is the eye

Back 29

A converging lens.

Front 30

When ciliary muscles contract, the lens becomes more ______shaped . When the ciliary muscles relax, the lens comes more ___

Back 30

sphere like.
flat

Front 31

Sensory receptors ____ physical stimulus to neural signals.

Back 31

transduce

Front 32

cones distinguish ____ & ____ dont.

Back 32

color
rods

Front 33

Nervous system is split into ___.

Back 33

CNS and PNS

Front 34

CNS is ___

Back 34

Brain,
Spinal Cord

Front 35

PNS is ___

Back 35

All other stuff than brain and spinal cord.

Front 36

PNS is split into ____.

Back 36

Somatic (skeletal muscle)
Autonomic (automatic, smooth muscle etc)

Front 37

Autonomic is split into ___

Back 37

Sympathetic
Parasympathetic

Front 38

Parasympathetic -

Back 38

"rest and digest"
It deactivates most stuff and activates intestines and excretory system.

Front 39

Sympathetic -

Back 39

"fight or flight"
It activates heart and major skeletal muscles, dilates your pupils for night hunting, redirected blood from digestive and excretory systems

Front 40

____ - covers the inside of the back (distal portion) of the eye
It contains light sensitive cells called cones & rods.

Back 40

Retina

Front 41

cones ->

Back 41

color

Front 42

Action potential (5) steps -

Back 42

1. Membrane is at rest. Sodium and potassium channels are closed.
2. Sodium channels open and the cell depolarizes.
3. Potassium channels open as NA+ channels begin to inactivate.
4. NA+ channels are inactivated. Open K+ channels repolarize the membrane.
5. K+ channels close and the membranes equilibrates to its resting potential.

Front 43

____ - nonvascular collagen

Back 43

cornea

Front 44

(3) small bones of the middle ear

Back 44

Mallus
Incus
Stapes

Front 45

_____ carry signals to a muscle or gland called the effector.

Back 45

motor (efferent) neurons

Front 46

The postganglionic neurons of the sympathetic nervous system use either ____.

Back 46

epinephrine or norepinephrine
(adrenaline or noradrenaline)

Front 47

The autonomic nervous system is ____ and innervates cardiac and smooth muscle and some glands.

The somatic nervous system innervates ____.
Autonomic pathways are controlled mainly by the ____.

Back 47

involuntary
skeletal muscle
hypothalamus

Front 48

Lower brain -
higher brain -

Back 48

medulla, hypothalamus, thalamus, cerebellum

Cerebrum or Cerebral Cortex

Front 49

For the Mcat think of the ____ as the brain and spinal cord and the ___ as everything else.

Back 49

CNS
PNS

Front 50

When an action potential is generated down a myelinated axon, the action potential jumps from one node of Ranvier to the next as quickly as the disturbance moves through the electric field between them. This is called ____.

Back 50

saltatory conduction

Front 51

White matter -
Gray matter -

Back 51

myelinated axons appear white
neuronal cell bodies appear gray

Front 52

gaps between myelin -

Back 52

nodes of Ranvier

Front 53

Oligodendrocytes wrap many times around axons in the central nervous system creating electrically insulating sheaths called _____.

Back 53

myelin
(typically not in the brain)

Front 54

_____ produce myelin in the peripheral nervous system.

Back 54

Schwann cells

Front 55

Chem synapse
It is the ____ step in the transfer of a nervous signal and it can only transfer signal in ____ direction.

Back 55

slowest
one

Front 56

2nd messenger system -

Back 56

activating another molecule inside the cell to make changes

Front 57

The ____ attaches to its receptor for only a fraction of a second and is released back into the synaptic cleft.

Back 57

Neurotransmitter?

Front 58

"gap" between the presynaptic neuron and the postsynaptic neuron

Back 58

synaptic cleft

Front 59

random motion of molecules , the movement across the cleft

Back 59

Brownian motion

Front 60

____ - w/ few exceptions, the neurotransmitter used by all preganglionic neurons in the ANS and by postganglionic neurons in the parasympathetic system

Back 60

acetylcholine

Front 61

Neuron processes (axons and dendrites) are typically bundled together to form ____.

Back 61

Nerves

Front 62

(3) possible neuron functions

Back 62

1. Sensory (afferent) neurons
2. Interneurons
3. Motor (efferent) neurons

Front 63

Sympathetic ->
Parasympathetic ->

Back 63

"Fight or Flight""
"Rest & Digest"

Front 64

____ transfer signals from neuron to neuron. 90% of neurons in the human body are these.

Back 64

interneurons

Front 65

____ - respond to the external environment, motor neurons innervate only skeletal muscle

Back 65

Somatic Nervous System

Front 66

____ - involuntary, further broken into sympathetic and parasympathetic

Back 66

Autonomic Nervous System

Front 67

____ receive signals from a receptor cell that interacts with its environment.

Back 67

sensory (afferent) neurons

Front 68

Neural impulses are transmitted from one cell to another chemically or electrically at a ____.

Back 68

synapse

Front 69

Chemical Synapse is ____.

Back 69

called a motor end plate when connecting a neuron to a muscle
unidirectional

Front 70

____ - are uncommon. they are composed of gap junctions between cells. Cardiac muscle, visceral smooth muscle and very few neurons in the central nervous system contain electrical synapses. Faster then ____ in both directions.

Back 70

Electrical Synapses
Chemical

Front 71

These proteins change configuration when the voltage across the membrane is disturbed.

Back 71

voltage gated sodium channels

Front 72

Where the membrane potential reverses polarity, so it is positive on the inside and negative on the outside.

Back 72

depolarization

Front 73

____ - when the inside membrane becomes even more negative than the resting potential.

Back 73

hyperpolarization

Front 74

____ - process involving voltage gated potassium channels & K+ flowing out of the cell making the inside more negative

Back 74

repolarization

Front 75

An action potential is -

Back 75

all-or-nothing, the membrane completely depolarizes or no action potential is generated

Front 76

In order to create an action potential, the stimulus to the membrane must be greater than the ____.

Back 76

threshold stimulus

Front 77

A signal travels from the ____ to the ____, where an ____ is generated and moves down the ____ to the synapse. Neurons do not depend on ____ to obtain glucose.

Back 77

Dendrite
Axon Hillock
Axon potential
Axon
Insulin

Front 78

____ - is established mainly by an equilibrium between passive diffusion of ions across the membrane and the Na+/K+ pump.

Back 78

Resting potential

Front 79

____ - A disturbance in the electric field across the membrane of a neuron.

Back 79

Action Potential

Front 80

____ - carries the action potential to a synapse, which passes the signal to another cell.

Back 80

axon

Front 81

Typically, the cytosol of the cell (nervous) body is highly conductive and any electrical stimulus creates a disturbance in the electric field that is transferred immediately to the ____.

Back 81

axon hillock

Front 82

____ - receive a signal to be transmitted

Back 82

dendrites

Front 83

Neurons basic anatomy -

Back 83

many dendrites
a single cell body
usually one axon w/ many small branches

Front 84

____ - the functional unit of the nervous system

Back 84

neuron

Front 85

The 3 body "communication" systems

Back 85

Endocrine - Hormones (anger)
Paracrine - Very local Hormones (mm away)
Nervous - direct.., bend your arm

Front 86

Slower, spread throughout the body and affect many cells and tissues in many different ways is ____ communication.

Back 86

Hormonal

Front 87

Rapid, direct and specific is ____ communication.

Back 87

Neuronal

Front 88

Interstitial Fluid -

Back 88

Fluid between the cells

Front 89

___ - the stuff that surrounds the cell and is formed by the cell itself.

Back 89

extracellular matrix

Front 90

Mitochondria -

Back 90

powerhouse of a eukaryote cell

Front 91

Parts of a mitochondria -

Back 91

2 phospholipid bilayers
innermembrane invaginates to form cristae. (holds the electron transport chain)
Between inner & outer is the intermembrane space

Front 92

____ in cardiac muscle provide for the spread of the action potential from cell to cell.

Back 92

Gap Junctions

Front 93

____ - small tunnels connecting cells they allow small molecules and ions to move between cells.

Back 93

gap junctions

Front 94

____ - like "spot welds" holding cells together

Back 94

desmosomes

Front 95

____ - attach directly to the cytoskeleton of each cell. They are normally found in tissues that experience a lot of stress and they often accompany tight junctions.

Back 95

desmosomes

Front 96

(3) types of cellular junctions

Back 96

Desmosomes
Tight junctions
Gap junctions

Front 97

____ - form a "watertight" seal from cell to cell that can block water, ions and other molecules from moving around and past cells.

Back 97

tight junctions

Front 98

____ - think of the 6-ring plastic holder the cans are the cells.

Back 98

tight junctions

Front 99

____ - the polymerized protein that forms a major component of microfilaments.

Back 99

actin

Front 100

Cross bridges made from a protein called ____ connect each of the outer pairs of microtubules to their neighbor.

Back 100

dynein

Front 101

The major portion of each flagellum and cilium ____, contains 9 pairs of microtubules forming a circle around 2 lone microtubules in an arrangement known as 9 + 2.

Back 101

axoneme

Front 102

____ - responsible for amoeba-like movement

Back 102

cytoplasmic streaming

Front 103

The major MTOC (microtubule -organizing-center) in animal cells is the _____.

Back 103

centrosome

Front 104

function in the production of flagella and cilia -

Back 104

centriole

Front 105

Microtubules vs Microfilaments (tubules)

Back 105

Microtubules: larger, involved in flagella and cilia construction and the spindle apparatus

Microfilaments: squeeze the membranes together in phagocytosis and cytokinesis. Also the contractile forces in microvilli and muscle

Front 106

Eukaryotic Flagella is not Prokaryotic Flagella

Back 106

Eukaryotic are made form a 9+2 microtubule configuration. Prokaryotic flagellum is a thin strand of a single protein called flagellin. Eukaryotic undergo a whip-like action , prok rotate.