Biochemistry 1 Flashcards
(189 cards)
1
Q
What are the 6 atoms that make up 99% of all living organisms? From most abundant to least.
A
Most to least:
Oxygen, Carbon, Hydrogen, Nitrogen, Phosphorous, Sulfur
2
Q
Matter
A
Any substance in the universe that has mass and occupies space composed of particles called atoms
3
Q
What are the smallest unit of any given element?
A
Atom
4
Q
What are atoms composed of? Which is the most important in bonding?
A
Protons (+), Electrons (-) and Neutrons (n0). Electrons are the most important in bonding because they are what pulls two atoms together.
5
Q
6
C
Carbon
12.011
Label each component.
A
6 -> atomic number (# of protons and electrons)
C-> symbol
12.011 -> the mass number (protons + neutrons)
6
Q
Isotopes
A
different forms of the same element that vary in the number of neutrons (different atomic mass)
-but they have the same properties
7
Q
If a carbon isotope has 6e,6p, and 7n, what is it’s name?
A
Remember mass number = neutrons + protons
So 7+6=13
Answer: carbon-13
8
Q
Why do isotopes have the same chemical properties?
A
Because they contain the same number of electrons
9
Q
Radioisotopes
A
Radioisotopes are isotopes which their nucleus are so unstable they decay and give off radioactive particles
10
Q
What are radioisotopes useful for?
A
-radioactive tracers
-nuclear medicine
-radiometric dating
-dna sequencing
11
Q
What do isotopes of the same element differ and remain similar in? (summary)
A
Similar
-number of protons and electrons
-chemical properties
Differ
-the atomic mass
-the number of neutrons only
12
Q
What is the chemical behaviour of an atom determined by?
A
It’s electron configuration in its outermost shell (valence/electron shell)
-atoms with incomplete valence shells are chemically reactive
13
Q
Octet Rule
A
atoms tend to gain, lose, or share electrons so they have have a full valence shell
14
Q
What are ions
A
Charged particles which are either positively charged (cation) or negatively charged (anion) which form by gaining or losing electrons
-between metal and non-metal
15
Q
Covalent bonds vs Ionic bonds
A
Covalent - formed by sharing of electrons -> forms molecules
Ionic - transfer of electrons -> forms ions
16
Q
What is VSEPR theory?
A
Valence shell electron pair repulsion theory (VSEPR)
-electrons try to get as far away from each as possible
-lone pairs of electrons take up more space than bonding pairs of electrons
17
Q
Why does water have a bent shape?
A
VSEPR, the electrons repulse each other, the lone pairs on the oxygen molecule repulse the hydrogens making it asymmetrical
18
Q
What is the electronegativity?
A
The measure of how strongly an atom is going to pull shared electrons towards itself
19
Q
EN values of non-polar covalent, polar-covalent, and ionic compounds
A
NPC - 0-0.4
PC - 0.5-1-6
IB - EN > 1.7
20
Q
non-polar covalent, polar-covalent, and ionic compounds
A
Non-polar -> symmetrical, equal sharing of electrons, no charge separation
Polar -> unequal sharing of electrons, charge separation
Ionic -> transfer of a charge (electron)
21
Q
Why are compouds polar/nonpolar?
A
Due to their electronegativities, which is their ability to hold onto electrons, if an electronegativity is low then they just share it quite equally.
22
Q
How to determine where the partial -/+ charges are
A
The more electronegative atom contains the partial negative charge
23
Q
Ranking of bond strengths:
A
ionic > polar > non-polar
24
Q
Why are polar molecules stronger than nonpolar molecules?
A
The symmetry, the type of bonds between, the atoms involved, etc.
25
Asymmetrical =
Symmetrical=
asym = polar
sym = non-polar
26
London Forces
Van der waal forces, they exist between all molecules and are the weakest ones
27
Explain water as an example of bonds (detail)
water is a covalent bond between H and O
-O is more EN therefore it contains the partial negative
-O attracts the hydrogen more than the hydrogen attracts O therefore it has asymmetrical strength
-water has a bent shape
28
Dipole-dipole forces
exist between polar molecules polar ends which attract each other
29
Hydrogen bonds
A type of strong dipole-dipole force which bonds together H-F H-O H-N
FON
30
Ion-dipole interactions
Form between an ion and a polar molecule
Example: hydration shells
31
Hydration shells
Polar molecules attract to the negative/positive charges on ions and form a shell to dissociate them.
Water dissolving NaCl
32
Hydrophilic vs Hydrophobic
Hydrophilic - water loving, polar charged molecules
Hydrophobic - water fearing, non polar molecules
33
Like dissolves like
polar molecules dissolve in polar molecules, etc.
34
Why do oil and water not mix?
When a nonpolar molecule such as oil with no charges on it are put in a polar molecule, the polar molecules are going to attract to each other's charged ends which pushes the nonpolar molecules out of the way
35
Liquid vs solid water
-when is water most dense?
-which state is more dense?
-what structure does water form?
Water is most dense at 4C
Less dense as solid than as liquid
This means ice can float on water
Water forms a water lattice
36
What is special about water at room temperature?
Water is liquid at room temperature due to its water lattice structure, which most molecules of similar size would be gases
37
Specific heat capacity
The amount of energy required to increases the temperature by 1 degree celsius
- a lot of energy is need to increase temperature of water
38
Cohesion vs adhesion
Cohesion - water molecules stick to each other well through hydrogen bonds
Adhesion - water molecules form hydrogen bonds with other polar molecules (sticking to container walls)
39
The four major types of chemical reactions that are common in biological processes are:
-condensation
-hydrolysis
-neutralization
-redox reactions
RCHN
40
What is surface tension a property of water?
Cohesion
41
How is high specific capacity beneficial for organisms?
It helps organisms maintain a steady body temperature
42
What happens when pH levels change in the body?
must be maintained at very exact level, if it changes it could denature proteins and enzyme function
43
Buffers
used to control pH levels inside cells since they can absorb or release H+ ions
44
What kind of buffers are in blood?
Bicarbonate buffers
45
Why is carbon so special?
-4 covalent bonds
-can form long chains that can be straight or branched
-can form ring structure
-it can form branches in up to four directions
-can bond to itself or other atoms
46
Hydrocarbons
contain only carbon and hydrogen
47
Alkanes, Alkenes, Alkynes, cyclic
Alkanes = all single bonds
Alkenes = one or more double bonds
Alkynes = one or more triple bonds
Cyclic = ring structures
48
Functional groups
group of atoms on HC chains that give molecules certain physical properties
49
Dehydration synthesis reactions
removing water to combine two molecules (condensation reaction)q
50
Hydrolysis Reactions
breaking apart molecules with water
51
Carbohydrates use
-quick, short term forms of energy
-important for structural molecules
-sugars and simple starches/sugars
52
Carbohydrates ratio
1:2:1
C1:H2:O1
53
Monosaccharides
+ 3 main types
Simplest type of carbohydrate found in cyclic structures in cells, they consist of single sugar units; building blocks for more complex carbohydrates
-glucose, fructose, galactose
53
Disaccharides + three main types
A carbohydrate molecule that consists of two monosaccharides
-sucrose, lactose, maltose
54
What happens when monosaccharides linear are in water?
They form ring structures especially by the functional groups react with each other
55
isomers
a molecule that has the same chemical composition, but different arrangements of atoms
56
Types of glucose
alpha and beta glucose
Alpha - the OH on the right side is down
Beta - the OH on the right side is up
57
Why are sugars so soluble in water?
They have a lot of functional groups attached to them
58
Draw glucose and galactose
Draw
59
What's the difference between glucose and galactose? What are these called?
Glucose and galactose are isomers, they have the same chemical formula, but different properties
LEFT SIDE
-galactose the OH is up
-glucose the OH is down
60
How are disaccharides brought together
By dehydration synthesis reactions
61
How does maltose form
1-6 or 1-4 alpha linkage of two alpha glucose molecules
62
What kind of bond links together monosaccharides
Glycosidic bonds
63
How does lactose form
galactose + glucose
64
How do you tell if a glycosidic bond is alpha or beta
The orientation of the -OH group on the first carbon
65
Solubility of types of carbohydrates
Mono - very soluble (functional groups)
Di - they are also soluble
Poly -they are hydrophilic (attract water) but since they are so long they don't dissolve in water
66
Types of bonds that can form maltose
1-4 alpha glycosidic bond
or
1-6 alpha glycosidic bond
67
Draw hydrolysis and dehydration synthesis of two alpha glucose
draw
68
Polysaccharides + main functions
Complex carbohydrates that is composed of hundreds to thousands of monosaccharides linked together
-provide structural support and energy storage
69
Types of macromolecules
proteins, lipids, carbs, dna/rna
70
Polymerization
when monomers link together through dehydration synthesis to form long chains of a larger molecule
71
Celluose structure and function
Structural support in plants cell walls
Made of b-glucose units that flip opposite ways
also known as fibre
72
Difference in how cellulose and starch affect our bodies
We have enzymes that digest starch and turn it into glucose monomers but not cellulose so it comes out in excretion
73
Starch function
Starch is an energy storage molecule in plants
74
Types of starch molecules and their difference + the difference in looks (draw)
both glucose
Amylose -> straight chains alpha 1-4 GB (curly and straight)
Amylopectin -> branched a 1-4 a-1-6 GB (branched)
75
Glycogen
Most branched type of polysaccharide
1-4 1-6 alpha
-They are storage molecules found in animals
-liver muscles
76
Starch vs cellulose
starch = alpha 1-4 bonds of glucose monomers
cellulose = flipped every other beta 1-4 bonds of glucose monomers
77
Lipids definition and function
non-polar molecules made of most carbon, hydrogen, and oxygen
-they are used for LONG term energy storage
-important components of cell membranes and signalling molecules
78
Fatty acids composition
Contain a carbon hydrocarbon chain and a carboxyl group on one end
79
Unsaturated fatty acids vs saturated fatty acids
Unsaturated
-double or triple bonds
-they have kinks
-more space between them
-generally healthier
-normally liquid
-cis and trans
Saturated
-single bonds
-straight chains
-more packed together
-normally solid
-unhealthier
80
What does polyunsaturated mean
When there's more than one double or triple bond in an unsaturated fatty acid
81
Types of unsaturated fatty acids
Cis
-the carbons are on the same side of the double bond
-"kink"
Trans
-carbons are on the opposite side of the double bond
-straight chains
-less flexible than saturated
-worst type of fats
82
why are trans and saturated fats so bad?
-raises bad cholesterol and lowers good cholesterol
-trans fat introduce more cholesterol and saturated fats into the cell membrane (both containing straight chains), which in normal amounts is fine, but when it's too high, it will make the membrane too rigid so its difficult for nutrients and molecules to pass through
-less flexible and can't change to environment
83
Fats (triglycerides)
Contain a glycerol molecule + three fatty acid chains (can be different fatty acid chains)
84
What bonds together fats + how to locate it
Ester bonds C-O-C=O form by dehydration synthesis reactions
85
Draw a triglyceride
draw
86
Phospholipids
-primary component of cell membranes
-contain a polar head (the phosphate group)
-the non-polar tail (the fatty acid chains)
-glycerol backbone
87
Phospholipids
Contain glycerol bonded to two fatty acids and a phosphate group
-primary component of cell membranes
-contain a polar head (the phosphate charged group) and nonpolar tails (fatty acids)
88
Warm blooded animals are most composed of...
Saturated fats but these fats tend to be liquid due to high body temperature.
89
Triglycerides function
-they are for long term energy storage and are an excellent source of energy in a diet.
-insulation in mammals and birds
-they tend to be used last
90
If lipids contain more energy than carbohydrates, then why are carbohydrates used first for energy rather than lipids?
Carbohydrates yield energy much faster than lipids
91
Steroids
lipids that have four fused carbon rings wide certain side groups that give it certain properties
-many hormones are steroids
92
Cholesterol
essential steroid for cell membranes
-too much is bad for you
93
Waxes
Fatty acid chains linked to alocohols or carbon rings
-very hydrophobic, provide waterproof protection for plants and animals
94
Proteins
Proteins are essential parts of living organisms and participate in virtually every process in cells EXCEPT energy storage
95
Types of proteins (6)
Enzymatic, structural, transport, hormonal, contractile, defensive
96
What are proteins composed of
amino acid monomers
97
Draw and label an amino acid
draw
-central carbon
-amino group
-carboxyl group
-R group
98
What are R groups
the group of atoms which give amino acids their individual properties
99
What are the '8 essential amino acids'
There are 20 amino acids and 8 of them are essential for the human diet because they can only be obtained from the diet, the rest can be synthesized by cells
100
Types of amino acids
-non polar
-polar
-charged acidic (-)
-charged basic (+)
101
What are amino acids linked together by
peptide bonds (C-N) which are formed through dehydration synthesis between -NH2 and -COOH
102
What is a polypeptide
A sequence of amino acids joined together by peptide bonds
103
C and N terminal in an amino aicd
C - the COOH end
N - the NH2 end
104
Protein vs polypeptide vs peptide
peptide = group of amino acids bonded
polypeptide = 50 or more of those peptides
proteins = a bunch of polypeptide folded into a three-dimensional shape -> only after folding can protein function
105
Protein structure (4)
Primary structure - specific sequence of amino acids joined together by peptide bonds called a polypeptide, a single chain can alter or destroy the biological function
Secondary structure - The *hydrogen bonding* between the backbones of amino acid (everything except the R group) = forms alpha helix and beta pleated sheets
alpha =coiled sheet
beta = side by side arrangement
Tertiary structure - Interactions between the side groups (R groups)
-ionic bonds (between charged a.a), hydrogen bonds (polar a.a), hydrophobic interactions (non polar a.a), -SH groups of two a.a line up and form S-S and hold the a.a together (covalent bond between cysteine a.a)
Quartenary sturcture - two or more folded polypeptide come together to make the final functional protein
-polypeptides can be held together by the same bonds as the tertiary sturctures (ionic, hydrophobic, hydrogen bonds, disulfide)
-important step for function of proteins and stabilizing the shape
106
20^n
If there are 3 amino acids, how many possibilities?
n= number of amino acids
8000
107
Denaturation
when a protein loses its structure and function due to pH, heat
-usually irreversible
108
Nucleic Acids function + monomer
Biological polymers
-contain genetic information
-instructions for proteins
-monomer is nucleotide
109
What is a nucleotide composed of
Sugar + phosphate group + nitrogenous base
110
Deoxyribose vs ribose sugar
2' carbon on deoxy has H only and on ribose has OH
111
Types of nitrogenous bases
pyrimidines (tombs, coffins, uprising) - thymine, uracil, cytosine
Purines (GAGA baby) - guanine and adenine
112
What are nucleotides bonded together by?
Phosphodiester bonds 5'-3'
113
DNA vs RNA function
DNA
-contains the genetic and hereditary information
-has the instructions for building
-ATGC
-ribose
-double
-stays in nucleus
RNA
-transfer information from DNA and send it out to ribosomes which take instructions and form proteins
-AUGC
-deoxyribose
-single
-made in nucleus
114
What bonds hold together DNA strands
hydrogen bonds in between bases and phosphodiester bonds between sugar phosphate backbone
115
Hydroxyl group
Class of compounds
Diagram
Ionic or polar
Found in
Class: alochols
Diagram: -OH
I/P: Polar (dipole-dipole)
Found in: carbohydrates, glycerol
116
Carbonyl
Class of compounds
Diagram
Ionic or polar
Found in
Class of compounds: ketones/aldehydes
-ketones are in middle, aldehydes are at end
Diagram: C=O, C=O-H
Ionic or polar: polar (H-bonds)
Found in: carbohydrates
117
Carboxyl
Class of compounds
Diagram
Ionic or polar
Found in
Class of compounds: carboxylic acids
Diagram: OH-C=O
Ionic or polar: polar, H-bonds
Found in: amino acids, fatty acids
118
Ester
Class of compounds
Diagram
Ionic or polar
Found in
Class of compounds: esters
Diagram: C-O-C=O
Ionic or polar: polar
Found in: Fats/lipids
119
Phosphates
Class of compounds
Diagram
Ionic or polar
Found in
Class of compounds: phosphates
Diagram:
O
|
O-P-O
||
O
Ionic or polar: IONIC
Found in: nucleic acids
120
Sulfhydrul
Class of compounds
Diagram
Ionic or polar or nonpolar
Found in
Class of compounds: thiols
Diagram: -S-H
Ionic or polar: non-polar
Found in: cysteine (amino acids)
121
Amino
Class of compounds
Diagram
Ionic or polar
Found in
Class of compounds: amines
Diagram: -NH2 or -NH3+
Ionic or polar: polar (H-bonds)
Found in: amino acids
122
Nucleus function (4)
control centre of the cell
contains DNA which transcripts RNA
consists of the nuclear envelope, chromatin, and nucleolus, nucleoplasm, and nuclear pore
protects DNA from activity in the cytosol and metabolic reactions
123
Nuclear envelope
-Double membrane (2 layers of bilipid membrane)
-surrounds nucleus and protects DNA
-contains pores that allow materials in and out water and gas can pass freely
-membrane proteins are embedded inside: receptors and transporters
124
Nucleolus
The nucleolus is the densely packed ball of DNA and RNA and protein
visible in the cell only when the cell is not dividing
Makes rRNA used to make RIBOSOMES
125
Chromatin
Long threadlike strands of DNA
thicken and coil into chromosomes during cell division
set # per species (humans 46)
Total collection of all DNA molecules and associated proteins in the nucleus
126
centrioles
cylindrical organelles found near nucleus
each composed of nine tubes, each tube made up of three three microtubules
involved in cell division
release spindle fibres and microtubules
only in animal cells
127
Which organelle is only found in animal cells
Centrioles
128
Organelles with no membrane
Ribosome centriole
129
Nucleoplasm
the semifluid interior of the nucleus
130
Endomembrane system
Functions (5)
Which organelles are part of it?
the group of interacting organelles between the nucleus and the plasma membrane
function:
-make lipids, enzymes, proteins, and waste recycling and toxin destroying
Organelles: nucleus, rough ER (with ribosomes), vesicles, smooth ER, golgi body
131
Endoplasmic reticulum
An extension of the nuclear envelope
-folded compartments like flattened sacs
-rough and smooth
-can store substances like proteins
132
If a cell makes a lot of rough ER, what are its properties?
It will make, store, and secrete a lot of proteins
133
Smooth ER
Smooth ER
-no ribosomes
-some polypeptides made in rough ER end up in smooth ER as enzymes
-these enzymes produce most of the membrane lipids and break down carbs, fatty acids, and drugs/poisons
134
Rough ER
Rough ER
-ribosomes attached on surface and make polypeptide chains
-the ER folds the polypeptides and make final shape
-some become part of it or get carried to other parts of cell
135
Vesicles defintion (types not function just types)
Membrane bound sacs that are used to transport materials
-bud from other organelles or from the plasma membrane or their own
-transport proteins from one organelle to the other
types: peroxisome, vacuoles
136
Vacuoles
found in plant animal and plant cells used for
-storage of waste
-waste digestion
Plants
-structural support for plants
-filled with water
137
Lysosome
vesicles with powerful enzymes which fuse with vacuoles and empty their contents so vacuoles can digest them
Or can digest themselves
138
Golgi bodies
Look like sac of pancakes,
-vesicles fuse with this organelle and release contents
-enzymes inside put finishing touches on polypeptide chains and lipids delivered from ER
-attach phosphate groups and sugars
-cleave polypeptide chains
-end products are sorted and packaged into new vesicles that carry them to the plasma membrane or lysosomes
139
Mitochondria
powerhouse of the cell
make ATP
double membrane
convert glucose and oxygen into cellular energy
resemble bacteria in form and biochemistry
divide independently of cells
140
Which organelles have a double membrane
mitochondria, plastids (chloroplast), nuclear envelope
141
Plastids/Chloroplast
Double membrane
-contains green pigments chlorophyll
-carry out photosynthesis and storage
-only in plant/algae
-chloroplast is a type of plastid which also resemble bacteria
142
Cytoskeleton
-Between the nucleus and plasma membrane
system of filaments and structural support, helps with cell division
-enables movement of cells themselves -> muscles movement
-microtubules, microfilaments, intermediate filaments
143
Microfilaments/microtubules vs centrioles release
Centrioles make microtubules for the cytoskeleton and microfilaments/microtubules are components of the cytoskeleton
144
Cell wall
-only in plant cells
-cover the cell membrane
-made of cellulose fibres
-support and protection
145
Explain how phospholipids make the bilayer cell membrane
Polar charged phosphate hydrophilic heads face the outside and inside and the nonpolar tails make up the inner part.
146
Explain the difference between extracellular and intracellular fluid
Extracellular fluid is found outside of cells, surrounding it and intracellular is inside of cells they are separated by the plasma membranes
147
Why do phospholipids take on the shape that they have in aqueous solutions?
Because the tendency of the nonpolar hydrophobic fatty acids to aggregate together while the polar heads associate with water
148
Fluid Mosaic model def + 3 points
Our current view of membrane structure which is that membranes are not rigid, rather they are fluid
-proteins and molecules move around in the membrane.
-more unsaturated fats (kinks) make it more fluid
-it contains a "mosaic" mixture not just phospholipids
-proteins, carbs, cholesterol give the membrane structure and allow functions
149
Four types of membrane proteins (not function)
1.Transport proteins
2. Enzyme proteins
3. Signalling proteins
4. Attachment and Recognition Proteins
150
3 types of membrane protein orientations
Integral -> integral proteins go through but not fully
Transmembrane -> they go fully through the lipid bilayer
Peripheral -> only attached on the surface, do not interact with core, held by H-bonds and ionic bonds, sometimes attached to integral proteins
151
How do peripheral proteins help the cytoskeleton?
They serve as binding points for the cytoskeleton
152
What determines how proteins are oriented in the membrane?
The type of amino acids that make up the protein, for example the hydrophobic ones would be in the middle
153
Transport proteins function
Allow materials in/out of the cell through protein channels by changing shape or having certain charges
154
Enzymatic proteins
Perform reactions like respiration and photosynthesis
155
Signalling proteins
Bind to specific chemicals like hormones and trigger cascade of changes in the inner membrane
-the receptors
156
Attachment and recognition proteins
-attachment points for cytoskeleton elements
-cell to cell recognition
-bond to ECM
-recognize disease and trigger immune response
Note: these are transmembrane
157
Glycolipids and glycoproteins definition and function
Both are carbohydrate groups
glycolipids attach to lipids
glycoproteins attach to proteins
face ECM and they are like marking points for attachment/recognition by other cells and triggers response
158
What is membrane fluidity determined by (3) + how do they affect the membrane
-temperature (low=less fluid)
-unsaturated vs saturated membrane (unsaturated more fluid saturated less fluid)
-cholesterol (sterols) present (these stabilize membrane fluidity at high temperatures and more fluid at low temperatures)
when theres too much cholesterol it jams the membrane and makes it too rigid
159
Cholesterol in membranes and structure
Inside of the nonpolar fatty acid tails and
contain:
-hydrophobic tail
-hydrophobic end
-hydrophilic end
160
Membrane symmetry
Proteins and other components that make up the cell membrane are different on each side and functions are different
-binding of signalling molecules on the outside send change inside cell and begin signalling cascade (on signalling proteins)
161
What makes people depressed?
When serotonin doesn't bind properly to cell membranes therefore they are not able to use it and experience depression
162
What is diffusion
Movement of molecules down a concentration gradient (high to low) -> passive
163
What is passive transport
Transport that does not require energy
164
Why does diffusion occur?
Because when molecules are constantly in motion and become uniformly distributed to reach equilibrium where there is no net movement
165
What makes diffusion occur faster?
-Temperature
-SA:V ratio -> must be enough surface area to allow diffusion to occur
-the size of concentration difference
-size and charge of molecules
166
What is dynamic equilibrium
Particles continuing to move even after equilibrium is reached
167
Simple diffussion
substances moving across a membrane unassisted
Includes:
-small nonpolar molecules O2, CO2, N2
-small, uncharged polar molecules H2O, glycerol
Rejects large molecules and ions like glucose, sucrose, Cl-, Na+, K+
168
Facilitated Diffusion, why is it used?
Some molecules may need to pass the cell membrane faster or they are too large to go through the membrane so transport proteins are used to move them
-it is still based on a concentration gradient
169
Two types of transport proteins
Carrier proteins
Channel proteins
170
Carrier proteins
They help molecules move down a concentration gradient by changing shape
-passive transport
-recognize molecules based on shape (very specific)
-only move uncharged molecules
-example: glucose
-changes shape to release
171
Channel proteins
-contain polar/hydrophilic or charged tunnel-like membranes
-attract polar molecules or ions of OPPOSITE charge and allow them to pass through the bilayer
-recognizes the molecules based on charge and size
-example ion channels
172
Why would fructose not go through a glucose carrier protein? Why is this important
Membrane proteins are very specific and only bind to the specific solutes they carry. This is important because it ensures tight control over what goes in and out of cells
173
What influences rate of facilitated diffusion in membranes?
The size of the concentration gradient and the number of transport proteins available
-> in faciliated diffusion, the maximum rate of transport is reached quickly, but its limited by the number of proteins so the rate plateaus.
-> in simple diffusion its a pretty linear rate
174
Osmosis
Difussion of water from an area of high to low concetration
-passive
-causes cells to shrink/swell
175
How does water move
High water, low solute -> low water, high solute
176
Osmosis
Diffusion of water from an area of high to low concentration
-passive
-causes cells to shrink/swell
177
Isotonic
equal water and solute concentration in cells
-no net movement
178
A cell in a hypertonic solution
There is more solute and less water in the solution which will make water move out of cell and SHRINK
179
A cell in a hypotonic solution
There is less solute and more water in the solution which makes water move into the cell and BURST/SWELL
180
Active transport
Moving molecules against an electrochemical concentration gradient using energy
Low -> high concentration
181
If a muscle cell needs 30x the calcium concentration outside the cell than inside, what mechanism does it use?
It will use active transport to move against a concentration gradient and keep the difference
182
Explain primary active transport steps
1. ATP hydrolyzes into ADP and phosphate and then the P group attaches to the membrane protein turning it into a high energy state
2. The ion binds
3. Once the ion binds, it folds to opposite side and reduces binding strength of ion
4. releases ion and phosphate
5. protein goes back to normal shape
183
What are endocytosis/exocytosis used for?
Bulk transport of molecule that are too large to cross through membrane, proteins, whole cells
-both use energy/ATP
184
Endocytosis + types
Bring large molecules inside cell
-phagocytosis
-pinocytosis
-receptor assisted
185
Phagocytosis
Eating (cell takes in large amount of ECF can include large whole cells or bacteria)
-only occurs in special cells like amoeba, immune cells
-cell extends false feet until vesicle is formed
186
Pinocytosis
Drinking (cell takes in ECF and whatever molecules in it)
-occurs in all cells
187
Receptor assisted endocytosis
Receptors on the membrane bind to specific molecules they recognize and initiates endocytosis
188
Exocytosis
Moving large or too polar molecules out of the cell
-vesicles fuse with membrane and release contents
-insulin secretion
