Nonenzymatic Protein Function And Protein Analysis

Front 1

these type of proteins compose the cytoskeleton, anchoring proteins, and much of the extracellular matrix

Back 1

structural proteins

Front 2

What are the most common structural proteins?

Back 2

collagen, elastin, keratin, actin, tubulin

Front 3

a repetitive organization of secondary structural elements together

Back 3

motif

Front 4

this has a characteristic trihelical fiber and makes up most of the extracellular matrix of connective tissue; it is found throughout the body and is important in providing strength and flexibility

Back 4

collagen

Front 5

this is an important component of the extracellular matrix of connective tissue and its primary role is to stretch and recoil to restore the original shape of the tissue

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elastin

Front 6

this is an intermediate filament protein found in epithelial cells; it is the primary protein that makes up hair and nails

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keratin

Front 7

this protein makes up microfilaments and thin filaments in myofibrils; it is most abundant in eukaryotic cells; the polarity of this protein allows motor proteins to travel along it unidirectionally

Back 7

actin

Front 8

this protein makes up microtubules which are important for providing structure, chromosome separation in mitosis and meiosis, and in intracellular transport

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tubulin

Front 9

Structural proteins are generally _________________ in nature.

Back 9

fibrous

Front 10

these proteins have one or more heads capable of force generation through a conformational change

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motor proteins

Front 11

Motor proteins have ___________ activity, acting as ATPases to power movement

Back 11

catalytic

Front 12

What are the 3 most common applications of motor proteins?

Back 12

muscle contraction, vesicle movement within cells and cell motility

Front 13

this is the primary motor protein that interacts with actin; each subunit of this protein has a single head and neck

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myosin

Front 14

in addition to its role as the thick filament in a myofibril, mysoin can be involved in what?

Back 14

cellular transport

Front 15

These are the 2 motor proteins associated with microtubules; they have 2 heads, at least one of which remains attached to tubulin at all times

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kinesins and dyneins

Front 16

these proteins play key roles in aligning chromosomes during metaphase and depolymerizing microtubules during anaphase of mitosis

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kinesins

Front 17

these proteins are involved in the sliding movement of cilia and flagella

Back 17

dyneins

Front 18

these proteins bind a specific substrate, either to sequester it in the body or hold its concentration at a steady state

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binding proteins

Front 19

List 3 common binding proteins

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hemoglobin, calcium binding proteins, DNA-binding proteins

Front 20

these allow cells to bind to other cells or surfaces and are all integral membrane proteins

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cell adhesion molecules

Front 21

these cell adhesion molecules are calcium dependent glycoproteins that hold similar cells together

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cadherens

Front 22

these cell adhesion molecules have two membrane-spanning chains called alpha and beta and permit cells to adhere to proteins in the extracellular matrix

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integrens

Front 23

this cell adhesion molecules allow cells to adhere to carbohydrates on the surfaces of other cells and are most commonly used in the immune system

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selectins

Front 24

these are used by the immune system to target a specific antigen, which may be a protein on the surface of a pathogen or a toxin

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antibodies

Front 25

what is another name for antibodies

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immunoglobins

Front 26

Immunoglobins contain what 2 regions?

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constant and variable

Front 27

this region of immunoglobins is responsible for antigen binding

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variable region

Front 28

What type of cells produce antibodies?

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B-cells

Front 29

Y-shaped proteins that are made up of 2 identical heavy chains and 2 identical light chains

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antibodies

Front 30

What holds the heavy and light chains together in antibodies?

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disulfide linkages and non-covalent interactions

Front 31

when antibodies bind to their antigens, it can mark the pathogen for destruction by other white blood cells immediately and this is called

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opsonization

Front 32

clumping together the antigen and antibody into large insoluble protein complexes that can be phagocytized and digested by macrophages

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agglutinating

Front 33

a process in which cells receive and act on signals

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biosignaling

Front 34

proteins that create specific pathways for charged molecules

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ion channels

Front 35

a type of passive transport that consists of the diffusion of molecules down a concentration gradient through a pore in its membrane; it is used for molecules that are impermeable to the membrane

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facilitated diffusion

Front 36

What are the 3 main types of ion channels

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ungated, voltage gated, ligand gated

Front 37

these channels are always open and are therefore unregulated

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ungated channels

Front 38

these channels are open within a range of membrane potentials

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voltage gated channels

Front 39

these channels open in the presence of a specific binding substrate, usually a hormone or neurotransmitter

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ligand gated channels

Front 40

these participate in cell signaling through extracellular ligand binding and initiation of second messenger cascades

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enzyme linked receptors

Front 41

these have a membrane-bound protein associated with a trimeric G protein and they also initiate second messenger systems

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G protein coupled receptors

Front 42

what engages the G protein?

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ligand binding

Front 43

In G protein coupled receptors, the activated alpha subunit alters the activity of what 2 possible things?

Back 43

adenylate cyclase or phospholipase C

Front 44

Gs ____________ adenylate cyclase, which _______________ levels of cAMP in the cell

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stimulates, increases

Front 45

Gi ___________________ adenlyate cyclase, which ___________ levels of cAMP in the cell

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inhibits, decreases

Front 46

Gq activates ______________________

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phospholipase C

Front 47

A G protein is in what form when the alpha subunit binds the GDP and is in a complex with the beta and gamma subunits?

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inactive

Front 48

this uses a gel matrix to observe the migration of proteins in response to an electric field

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electrophoresis

Front 49

How are proteins and other biomolecules isolated from body tissues or cell cultures?

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homogenization

Front 50

What is the equation for migration velocity?

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v=Ez/f

Front 51

what is the standard medium for protein electrophoresis?

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polyacrylamide gel

Front 52

this type of electrophoresis maintains the protein's shape but results are difficult to compare becasue the mass-to-charge ratio differs for each protein

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Native PAGE

Front 53

this type of electrophoresis denatures the proteins and masks the native charge so that comparison of size is more accurate, but the functional protein can not be recaptured from the gel

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SDS page

Front 54

this laboratory method exploits the acidic and basic properties of amino acids by separating on the basis of isoelectric point

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isoelectric focusing

Front 55

when does a protein stop moving in isoelectric focusing?

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when pH=pI

Front 56

What technique is preferred when large amounts of a protein are being separated: electrophoresis or chromatography?

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chromatography

Front 57

this separates protein mixtures on the basis of their affinity for a stationary or mobile phase

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chromatography

Front 58

when the sample runs through the stationary phase is chromatography

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elution

Front 59

the amount of time a compound spends in the stationary phase

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retention time

Front 60

varying retention times of each compound in solution results in separation of the components within the stationary phase and this is known as what?

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partitioning

Front 61

this type of chromatography uses beads of a polar compound (stationary phase) with a nonpolar solvent (mobile phase)

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column chromatography

Front 62

this type of chromatography uses a charged column and a variably saline eluent

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ion exchange chromatography

Front 63

this type of chromatography relies on porous beads; larger molecules elute first because they are not trapped in the small pores

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size exclusion chromatography

Front 64

this type of chromatography uses a bound receptor or ligand and an eluent with free ligand or a receptor for the protein of interest

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affinity chromatography

Front 65

After the protein is isolated its structure is primarily determined through what method?

Back 65

X ray chrystallography

Front 66

Amino acid composition can be determined by simple hydrolysis, but amino acid sequencing requires what?

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sequential degradations

Front 67

BCA assay, Lowry reagent assay, and Bradford protein assay each test for what?

Back 67

protein concentration