bio exam 2 Flashcards
(115 cards)
1
Q
4 types of biological molecules
A
- carbohydrates
- lipids
- nucleic acids
- proteins
2
Q
polymer definition
A
chains of smaller repeating molecules called monomers
3
Q
monomer definition
A
individual smaller molecules, individual links of polymers
4
Q
the reaction that a cell uses to build biological polymers
A
dehydration synthesis
5
Q
the reaction that a cell uses to break down biological polymers
A
hydrolysis
6
Q
peptide bond definition
A
special kind of covalent bond, connects amino acid monomers
7
Q
protein sequence definition
A
if we were to read the order of amino acids in a protein
8
Q
(T/F) proteins are polymers
A
true
9
Q
the molecules that are the monomers that proteins are built from
A
amino acids
10
Q
3 major parts of an amino acid
A
- alpha carbon
- amino group
- carboxyl group
11
Q
what makes up the amino acid backbone
A
- alpha carbon
- amino group
- carboxyl group
12
Q
what are the major parts that are the same on all 20 amino acids
A
contain side chains and backbone
13
Q
what are the major parts that are different between all 20 amino acids
A
differs by unique side chains
14
Q
4 chemical groups of amino acids
A
- negative (acidic sc)
- positive (nitrogen based sc act as bases)
- uncharged polar (hydrophilic and uncharged)
- nonpolar (hydrophobic)
15
Q
how do the 4 chemical groups of amino acids participate in the structure and function of a protein
A
frequently participate in chemical reactions that modify the protein structure and function
16
Q
between which parts of an amino acid do peptide bonds form
A
amino group – carboxyl group
17
Q
protein folding definition
A
protein folds into a 3D shape; occurs in.a series of distinct stages called levels of protein structure
18
Q
why is protein folding necessary
A
needs specific 3D shape to function properly
19
Q
4 levels of protein folding
A
- primary structure (unfolded)
- secondary structure (spiral alpha helices, sheet beta sheets)
- tertiary structure (3D ribbons)
- quaternary structure (many tertiaries)
20
Q
why are proteins able to fold
A
they form numerous non-covalent bonds
21
Q
which kinds of bonds allow proteins to fold
A
non-covalent
22
Q
about how many typically hold a protein in its shape
A
thousands
23
Q
how do non-covalent bonds contribute to protein structure at each of the 4 levels of protein structure
A
1P. chain of amino acids held by covalent peptide bonds
2S. non-covalent bonds between backbone atoms
3T. non-covalent bonds between side chains
4Q. non-covalent bonds between many amino acid chains
24
Q
4 types of non-covalent bonds
A
- electrostatic interactions (+-)
- hydrogen bonds (2 polar covalent)
- hydrophobic effect (non-polar away from water)
- van der waals attractions (2 nonpolar covalent)
25
how do the 4 types of non-covalent bonds allow amino acids to interact
1E. positive and negative amino acid
2HB. partially positive with partially negative
3HE. nonpolar side chains cause protein to fold so they pack tight
4VDW. nonpolar side chains shoved in protein
26
2 reasons why it is important to learn and understand protein folding
1. a protein's 3D shape is required for it to function properly
2. changes to a protein's 3D shape change the function of that protein
27
binding definition
protein attachment to other atoms and molecules for their ability to function
28
binding site definition
the specific place on a protein where it binds to another atom or molecule
29
conformation definition
a proteins 3D shape
30
ligand definition
the molecule or atom that a protein binds to
31
how does the 3D shape of a protein determine what kind of molecule it is able to bind
forms non-covalent bonds and must match very closely to 3D shape of its ligand
32
how is a binding site formed in a protein
the 3D folding of a protein
33
how does the 3D shape of a binding site allow it to bind to a ligand
specific amino acid side chains are positioned in specific places
34
denaturation definition
when a protein loses their 3D shape
35
how can proteins become denatured
chemical conditions can cause non-covalent bonds to weaken or break
36
what kinds of chemical conditions can cause denaturation
acid and heat
37
4 types of biological molecules and their building blocks (monomers)
1. proteins - amino acids
2. carbohydrates - monosaccharides
3. lipids - fatty acids
4. nucleic acids - nucleotides
38
3 groups of carbohydrates and their basic structures
1. monosaccharide - 1
2. disaccharide - 2
3. polysaccharide - 3+
39
major purpose of monosaccharides
glucose is the major energy source in most living organisms
40
major form of polysaccharide in the body and its basic structure and function
glycogen; liver and muscle stores glucose for energy in the form of glycogen
41
3 broad functions of carbohydrates
1. energy creation and storage
2. cell communication
3. building body structures
42
3 parts of a nucleotide
1. pentose sugar
2. phosphate group
3. nitrogenous base
43
basic structure and function of DNA
structure: strand of millions if nucleotides; double helix
function: has protein making instructions called genes
44
basic structure and function of ATP
structure: nucleotide with 3 phosphates
function: energy is temporarily stored by forming extra covalent bonds that release a lot of energy when broken by the cell
45
how do cells use ATP to store energy and do work
energy released from broken covalent bonds between peptides is used to do cellular work
46
3 basic types of cellular work done by the energy stored in ATP
1. transport work
2. mechanical work
3. chemical work
47
basic chemical properties of a lipid
- made from fatty acids
- hydrophobic
- not polymers
48
hydrophobic effect definition
clumping when hydrophobic molecules avoid water
49
3 types of lipid and their uses in the body
1. triglyceride - energy storage
2. steroid - cholesterol
3. phospholipid - phospholipid bilayer
50
basic structure of triglyceride and phospholipid, and how they differ
triglycerides - 3 fatty acid chains attached to glycerol
phospholipids - 2 fatty acid chains attached to glycerol
51
amphipathic definition
part hydrophobic, part hydrophilic
52
which type of lipid is cholesterol, and its use in the body
steroid; makes up all other types of steroids
53
nuclear envelope definition
flexible outer covering of the nucleus, double-layered
54
outer nuclear membrane definition
facing the cytoplasm
55
inner nuclear membrane definition
facing the inside of the nucleus
56
nuclear pore definition
protein based structure that regulates the movement of materials through the envelope
57
nucleolus definition
where ribosomes are assembled in the nucleus
58
functions of the central region of the nuclear pore and the central gate
space that proteins or other molecules can use to enter and exit nucleus ; central gate closes pore when not in use
59
why is it important that the central gate is leaky
lets small, necessary things in at all times
60
what types of things can and cannot leak through the central gate
can: small things
- atp
- oxygen
cannot: larger things
- proteins
- mrna
- ribosomes
61
how are molecules able to enter and leave the nucleus using nuclear import and export signals
they are keys included in their molecular structure
62
how are molecules like ribosomes and mRNA that are assembled in the nucleus, enter the cytoplasm
nuclear export signal
63
which sequences allow proteins to 1. stay in the cytoplasm, 2. stay in the nucleus, or 3. move between the cytoplasm and nucleus
1. nuclear export signal
2. nuclear import signal
3. both
64
signal sequence definition
tells the cell how and where to move each protein (proteins that stay in cytoplasm do not have signal)
65
what kind of signal sequence is found on proteins if they stay in the cytoplasm
none
66
endomembrane system definition and function
system of transport for proteins and other molecules through the cell
67
major structures that are part of the endomembrane system
- endoplasmic reticulum
- golgi apparatus
- plasma membrane
68
what kind of signal is needed to move proteins into the rough endoplasmic reticulum
ER signal sequence / ER import system
69
5 step process of moving a protein into the rough er
1. ER signal synthesized by ribosome
2. ER signal sequence binds to signal
3. signal recognition particle binds to receptor
4. SRP is released
5. ER signal sequence is removed
70
what kind of structure is used to move proteins through the endomembrane system once they are inside the er
signal recognition particle (SRP)
71
basic structure of golgi apparatus
cis network, cisternae, and trans network
72
cis golgi network definition
formed from vesicles heading to the golgi from the ER combining together
73
cisternae definition
the series of flat, pancake like memranes; the middle part of the golgi
74
trans golgi network definition
formed from vesicles heading back to the golgi from other organelles and the plasma membrane fusing together
75
how does the golgi sort proteins
proteins are places in vesicles based on their destination tags
76
what is a destination tag used for
tells golgi which vesicles to put them into and where to send it
77
exocytosis definition and how it works
when the transport vesicle combines with the plasma membrane, causing the material inside the vesicle to be released outside of the cell
78
endocytosis definition
the movement of materials into the cell
79
3 types of endocytosis and function of each
1. phagocytosis (cell eating; vesicle around large solid particles)
2. pinocytosis (cell drinking; vesicle around fluid outside the cell)
3. receptor - mediated endocytosis
80
3 things with which cells must constantly interact and communicate
1. with other cells that live in the same or nearby tissue
2. with the chemical and physical environment surrounding the cell
3. with the chemical and physical environment outside of the body
81
what are the types of fluid spaces
- intracellular fluid (ICF)
- extracellular fluid (ECF)
82
how do the chemical properties of the membrane / phospholipid bilayer allow it to function as a boundary between the cell and its environment
the hydrophilic heads face the water
83
permeability definition
a molecules ability to pass through a membrane
84
which molecules are naturally permeable
oxygen, carbon dioxide (small, non-polar molecules)
85
which molecules are not naturally permeable
large, polar
86
5 groups of membrane proteins
1. receptors
2. enzymes
3. cell identity markers
4. cell adhesion molecules
5. transporters
87
why are the 5 groups of membrane proteins needed in the membrane
receptors - binds to signal in ecf and transmits to icf
enzymes - speeds up chemical reactions
cell identity markers - identifies cells to other cells
cell adhesion molecules - attach to each other to stick cells together
transporters - moved hydrophilic molecules in and out of cell
88
which way do molecules diffuse
high concentration to low concentration of solute
89
difference between simple diffusion and facilitated diffusion
facilitated uses transport protein, simple does not
90
how do gasses move in the lungs by diffusion
oxygen diffuses into blood, carbon dioxide diffuses into the air
91
what is a concentration gradient
difference in concentration of a molecule between one place in the body and another
92
how does the size of a concentration gradient affect the rate of diffusion
larger the conc gradient, faster molecules will diffuse
93
limits of diffusion
movement into/through a cell by diffusion is limited by the amount of surface area for molecules to move through, and total volume of a cell or structure
94
how do our body structures have to be modified to maximize movement of molecules by diffusion
maximize surface area and volume of cells
95
2 ways that body structures increase surface area to volume ratio
1. folding or extending the cell membrane
2. building branched structures
96
what is osmosis and when does it occur
when there is a concentration gradient of an atom or molecule that cannot diffuse through the membrane
97
what direction does water move during osmosis
higher solute concentration
98
how does the flow of water during osmosis change water pressure
pressure lowers in the place the water leaves
99
osmotic pressure definition
water pressure created by the movement of water during osmosis
100
how does the size of a concentration gradient affect osmotic pressure
larger concentration gradient, higher osmotic pressure
101
relationship between energy and passive transport processes
no energy is spend in passive transport
102
what is the big limitation of passive transport
molecules can only be moved down the concentration gradient
103
what does it mean to move molecules up the concentration gradient, and how does active transport accomplish that
from low concentration to high concentration, using energy
104
pump definition
transport proteins that perform active transport
105
what does a sodium-potassium pump do and how
- allows Na to ECF
- allows K to ICF
- each cycle, 3 Na moved, 2 K moved, 1 molecule of ATP broken down
106
why do cells use energy to create the sodium and potassium gradients
they act as a battery for storing cellular energy
107
how can the sodium and potassium gradients be used to do work
work is done by the energy released by the diffusion
108
transport coupling definition
provides energy for active transport of another molecule instead of spending ATP
109
primary active transport definition
breaks down ATP to transport atoms or molecules
110
secondary active transport definition
uses the gradient created by the primary transporter
111
explain how transport coupling works SGLT1 in animal digestive system cells
SGLT1 couples the active transport of glucose to the diffusion of Na down concentration gradient
112
kinetic energy definition
energy doing work
113
potential energy definition
energy stored in an objects position or location
114
first law of thermodynamics
energy cannot be created nor destroyed, but it can be transformed from one form to another
115
