Lecture 2 Flashcards
Chapters 1b and 2a
1
Q
are K+ and Na+ same or different?
A
K+ is bigger in every way
more protons, neutrons, electrons). They have the same charge when dissolved in water (+1
2
Q
What person advanced the field of neuroscience the most?
A
Charles Darwin
3
Q
what was Charles Darwin’s idea
A
All animals in the world, all cells in the world have a lot in common, because they all are descendants of a common ancestor.
4
Q
The current diameter of our observable universe is what
A
91 billion light years
5
Q
The current diameter of our observable universe is 91 billion light years,
but this limit exists simply because why
A
of the slow speed of light.
The size of the entire universe might be 1023times this amount (no one knows).
6
Q
when did the universe expand
A
abou 14 billion years ago
7
Q
All the ordinary matter of the universe is made from what
A
the elements on the periodic table
8
Q
Achemical elementis what
A
an atom
9
Q
how long did inflation last?
A
less than a second but not sure how much
10
Q
Atoms have a specific number of what
A
protons
11
Q
when 2 atoms come together what is this called
A
a compound which makes a molecule
12
Q
if a molecule or singular atom has an electrical charge this is called what
A
an ion
13
Q
what is an ionic bond
A
when the charted particles come together
14
Q
what happens when an ion is dropped in water
A
breaks apart and dissolves
15
Q
Atoms held together by ionic bonds are called what
A
salts (like the table salt NaCl).
16
Q
A chemical reaction is what
A
when chemical bonds (chemical compounds) are formed, broken, or modified
17
Q
chemical reactions often involve what
A
These reactions often just involve a rearrangement of the electrons around the atoms involved
18
Q
The likelihood of a chemical reaction depends on many factors. Living entities (life) regulate chemical reactions to do what
A
create order, grow, and accomplish things.
19
Q
Planet Earth was formed when
A
4.5 billion years ago
20
Q
life as we know it formed when
A
Sometime in the 1st billion years
21
Q
The main elements of cells (of life on Earth) are:
A
The acronymCHNOPS, which stands for carbon, hydrogen, nitrogen, oxygen, phosphorus,sulfur, represents the six most importantchemical elementswhose covalent combinations make up mostbiologicalmoleculeson Earth
22
Q
what % of Hydrogen in the elements of cells (of life on earth) and what is the number of protons
A
59% Hydrogen (H, the element with 1 proton)
23
Q
what % of Oxygen in the elements of cells (of life on earth) and what is the number of protons
A
24% Oxygen (O, the element with 8 protons)
24
Q
what % of Carbon in the elements of cells (of life on earth) and what is the number of protons
A
11% Carbon (C, the element with 6 protons)
25
what % of Nitrogen in the elements of cells (of life on earth) and what is the number of protons
4% Nitrogen (N, the element with 7 protons)
26
what % of Others in the elements of cells (of life on earth) and what is the number of protons
2% Others (phosphorus, sulfur, …)
27
the CHNOPS are classified as what
non metals but reactive
28
The CHNOPS elements come together in different combinations to form a handful of different types of molecules such as: (5 of them)
```
Water
Sugar
Lipid
Nucleic acid
Amino acid
```
Almost everything found in a cell is one of these molecules or it is made up of a chain of these molecules (i.e., a chain of sugars or a chain of lipids, etc.)
29
what are lipids
the fat that makes o the cell wall
30
what are Nucleic acid
| Amino acid
made up of the same 6 elements but slightly diff orientation
| everything in cell that is not sugar water or fat is going to be made up of nucleic acid or amino acid
31
all molecules in a cell are what
long chains!
32
how many atoms are in any given part of the chain is the question
30-50 kinds of atoms in on blink but then you can get up yo million when looking at the longer chains
33
70% of total cell mass is what
water
34
Beside water (70% of total cell mass), cells are made up of:
15% Sugars (strings of sugar molecules are called carbohydrates)
10% Lipids (cell membrane, fat)
15% Nucleic acids (DNA & RNA are strings of nucleic acids)
50% Amino acids (proteins are strings of amino acids; the instructions for how to make proteins are found in the DNA)
10% Other organic molecules
35
strings of sugar molecules are calledwhat
carbohydrates
36
strings of nucleic acids are what
DNA & RNA
37
strings of amino acids are what
proteins
38
the instructions for how to make proteins are found where
in the DNA
39
what is plasma membrane
cell wall
40
The prokaryotic cell consist of a plasma membrane (cell wall) filled with what
cytoplasm
41
what is cytoplasm
which is mostly salt water
42
what was the first cell to appear on earth
prokaryotic
43
The prokaryotic cell consist of a plasma membrane (cell wall) filled with cytoplasm (which is mostly salt water). Floating in the cytoplasm are what
Loose strings of nucleic acids (DNA and RNA) - labeled chromatin
and
Proteins (made up of amino acids), which perform most of the functions within a cell.
44
Proteins are made by what
ribosomes
45
what are ribosomes made of
nucleic acids and proteins
46
Ribosomes form proteins how
by linking together amino acids (the building blocks of proteins) in the order dictated by the DNA genetic code.
47
what are proteins
Proteins are what do things in cells
48
are there lots of different types of proteins?
hell yes
49
what are Enzymes
Enzymes are proteins that perform (catalyze) chemical reactions
50
what are Receptors
Receptors are proteins that sense things and react accordingly
51
what make up the scaffolding and roads of a cell
Proteins are also what make up the scaffolding and roads of a cell. They also mediate transport and storage. They also serve as messengers
52
when did complex eukaryotic cells form
Sometime in next 2 billion years
53
what is required for a cell to move
ATP
54
what is ATP
energy
55
prokaryotic cells are always starved for what
energy
56
how are eukaryotic cells thought to have formed
there was a small bacteria (single cell) and some bigger ones
the bigger ones engulfed the smaller ones
normally would break it down to smaller parts but then it realized if it didnt break it down it would keep having energy and this formed a symbiotic relationship (the mitochondria was the cell that was engulfed and then not broken down)
57
The eukaryotic cell is similar, but it...
Organizes the DNA into a nucleus, from which the DNA cannot escape
and
2) It also has mitochondria, which are responsible for extracting energy from nutrients. This energy is typically stored in the molecular bonds of the molecule ATP.
58
what is the nucleus form
organized place to hold DNA
59
what do lysosomes do
garbage removal
60
A chromosome is a strand of what
DNA
61
A gene is what
a section (a functional unit) of a chromosome. It is a section of DNA unit that encodes a specific protein
62
When a gene is active (being read), copies of it are made (transcribed) into what
RNA
63
This RNA leaves the nucleus, where a ______ _______ into a protein.
ribosome translates
64
The genome of a cell (of an organism) refers to what
all the DNA sequences in the soma. The genome provides the information necessary to synthesize all the proteins for a particular organism.
65
Humans have about 20,000 protein-encoding genes in their genome.
Note, however, that genes can often be read in “alternative” ways, which can result in there being different versions of one type of protein. These protein variants are known as what
protein isoforms. Often several protein isoforms are made from a single gene
66
The Eukaryotic Cell Body is called what
Soma
67
The soma of a cell is where the what is located
nucleus is located
68
The nucleus houses what
the strands of DNA (the chromosomes) within a cell
69
Neurons are typically defined by what
where their soma are located (e.g. hippocampal neurons).
70
what is Cytoplasm
a gelatinous, semi- transparent fluid in which organelles are suspended.
71
what is Membrane
defines the outer boundary of the cell. It consists of lipids and is embedded with proteins that have special functions.
72
what are Microtubules
allow for rapid transport of material throughout the neuron.
like a highway system through the cell to move things efficiently
73
There are dozens of instances throughout history were collections of eukaryotic cells came together to form multicellular organisms.
Once multicellular organisms were formed, cells began to specialize, and the structure and function of life became almost limitless. Organisms known as animals first appeared when
around 650 million years ago
74
Nerve cells evolved when
600 million years ago
75
Nerve cells haven’t changed that much in the last hundreds of millions of years. So, to understand how human neurons work, you can study what animal
squid
76
The 1963 Nobel Prize was awarded for what (in relation to the squid)
describing how neurons transmit electrical signals, i.e. the action potential
77
The 2000 Nobel Prize was awarded for describing the neuronal basis of learning and memory.
This work was done on what
a sea slug
78
In the mammalian kingdom, brain structure is highly ______ between species
similar
79
why are rodents the dominant group of species used in neurobiology research
40% of the mammalian species alive today are rodents. 20% are bats.
Rodents are evolutionarily closer to humans than cats, dogs, bats, sloths, elephants, etc.
Because of the genetic and behavioural similarities between humans and rodents, as well as their small size, rodents have become the dominant group of species used in neurobiology research.
80
By learning what makes mice feel hungry or sexual, depressed or anxious, motivated or tired at the neuronal level what do we gain
we can get a very clear idea of how similar processes work in the human brain.
81
humans and chimpanzees share what percent of their DNA
98.8
82
After birth, the human brain continues to_____ __ ____ in a dramatic fashion
grow larger and heavier
83
do neurons keep producing
Production of new neurons almost ceases at birth, but those that are already present grow and establish connections with each other, and other types of brain cells, which protect and support neurons, begin to proliferate
84
what is Neoteny
extended youth – Prolongation of maturation
85
when does human brain reach its adult size of approximately 1400 g—about four times weight of newborn's brain
Not until late adolescence
86
Given the properties of planet Earth, how likely was the formation of life and evolution of intelligent, verbal beings?
Was this process fairly inevitable given the billions of years, or was it highly improbable?
Were we just lucky?
it was just a matter of time and evolution
mAYBE the development of language was a lucky thing because we are the only species with this complexity
87
what is the Fermi Paradox
where is everybody?
Within our galaxy, the Milky Way, there is estimated to be about 40 billion planets that could support life (earth-like planets).
The Milky Way galaxy is over 13 billion years old, so some earth-like planets may be much older than our relatively young planet earth.
If interstellar travel is possible, even the "slow" kind nearly within the reach of Earth technology, then it would only take from 5 million to 50 million years to colonize the Milky Way galaxy.
There is estimated to be over 2 trillion galaxies in our observable universe.
So, where is everybody?
88
what are Basic structure of the neuron
```
dendrites
terminal buttons
synapse
myelin sheath
soma (cell body
```
89
what is Soma (cell body)
contains the nucleus and is the metabolic centre of the neuron.
90
what are Dendrites
are branched, treelike extensions of the soma. They receive information from other cells and carry it to the soma
91
what are Terminal buttons
are button-like endings of the axon branch. They release neurotransmitters after receiving an action potential
92
what is synapse
Terminal buttons are button-like endings of the axon branch. They release neurotransmitters after receiving an action potential.
They connect with another neuron via a synapse, which is the junction between an axon terminal and the membrane of another neuron.
93
The axon carries information (via an action potential) from the soma to the axon terminals. It is often insulated by what
a fatty myelin sheath, which improves conduction velocity and fidelity
94
do Neurons have a resting membrane potential? what is it?
yes, -40 to -90 mV
| in nerve and muscle
95
The main elements of cells are:
```
59% Hydrogen (H)
24% Oxygen (O)
11% Carbon (C)
4% Nitrogen (N)
2% Others (phosphorus, sulfur, …)
```
96
what are the Positively charged ions
monovalent cations:
sodium (Na+), potassium (K+)
divalent cations :
calcium (Ca2+), magnesium (Mg2+)
97
what are the Negatively charged ions
monovalent anions:
chloride (Cl-)
divalent anions :
phosphate (HPO42-)
98
what is Intracellular fluid
Fluid contained within cells
99
what is Extracellular fluid
Fluid located outside of cells
100
Neurons sit in and are full of what
salt water
101
Neurons sit in and are full of salt water. The salt is mostly what
NaCl and KCl
102
The lipid bilayer is impermeable to what
ions
103
If there is an equal concentration of positively and negatively charged ions on either side of the membrane, then:
Outside of cell = 0 mV
| Inside of cell = 0 mV
104
potential is measured how
by comparing 2 things
105
Two proteins are responsible for setting up and maintaining the resting membrane potential of neurons:
Sodium-Potassium transporter (aka sodium potassium pump)
Leak potassium channels
106
what is Sodium-Potassium transporter (aka sodium potassium pump)
(requires ATP; concentrates sodium and potassium outside and inside the cell, respectively)
107
what are Leak potassium channels
(always open; the number of these channels dictates the resting membrane potential)
108
what happens with With the Sodium-Potassium Pump
K+ is pumped in while Na+ is pumped out
| required ATP to spin around a release
109
with Sodium-Potassium Pump, each is pumped in or out so There is no electrical charge difference yet (membrane potential = 0), since there are similar amounts of positive ions inside and out, but there is what
potential energy
110
There is no electrical charge difference yet (membrane potential = 0), since there are similar amounts of positive ions inside and out, but there is a potential energy here based on the force of diffusion.
what does this mean
Basically, the K+ ions feel crowded in the cell and want to leave
111
what is The Force of Diffusion
naturally wants to leave
Diffusion
Movement of molecules from regions of high concentration to regions of low concentration
When there are no forces or barriers to prevent them from doing so, molecules will diffuse from regions of high concentration to regions of low concentration
112
If you give K+ ions the freedom to leave the cell (by putting open potassium channels in the membrane), they will do so due to the force of diffusion.
These channels are called what
potassium leak channels
113
what happens if Outside of cell = 0 mV
| Inside of cell = -60 mV
The charge inside a neuron can reach -90mV before its electrostatic energy is equal and opposite to the force of diffusion.
The more leak channels a neuron has, the more permeable it is to K+ and the closer its membrane potential will be to the true equilibrium of these forces.
114
how many potassium ions need to leave the cell for the membrane potential to fall to -60 mV. This amount is actually very small (<0.0001% of the potassium ions inside the cell).
Tens of millions
115
Neurons vary in their expression of K+ leak channels, and typical resting membrane potentials range from what
40 to -90 mV
it will never actually get to -90... -60 is the typical!
116
is there always more K+ or Na+ in the cell?
always more sodium out than in and more potassium in than out
117
basically what is The Membrane potential
Balance of Two Forces
118
what are Ions
Charged molecule
Cations are positively charged
Anions are negatively charged
119
what is Electrostatic pressure
Attractive force between atomic particles charged with opposite signs or repulsive force between atomic particles charged with same sign
120
what are Ion channels
Specialized protein molecule that permits specific ions to enter or leave cells
121
what is Leak channel
K+ ion channel that is always open
122
what are the parts to The Force of Electrostatic Pressure
ion
electrostatic pressure
ion channels
leak channels
