Chapter 3 - Part 1 Flashcards
What are the primary structural proteins in the body?
- Collagen
- Elastin
- Keratin
- Actin
- Tubulin
What is the role of structural proteins
Structural proteins help the body maintain structure by making up the cytoskeleton of cells, anchoring proteins, the extracellular matrix, and connective tissue like tendons and ligaments.
What is Collagen?
Collagen is a characteristic, trihelical fiber. This protein makes up most of the extracellular matrix of the connective tissue. It is found throughout the body and is important in providing both strength and flexibility.
What is Elastin?
Elastin is another important component of the extracellular matrix of connective tissue. It’s primary role is to stretch and then recoil like a spring, which helps to restore the original shape of tissue after it has been deformed.
What is Keratin?
Keratin is an intermediate filament protein found in epithelial cells. Keratin contributes to the mechanical integrity of the cell and can also function as a regulatory protein. Keratin is the primary protein in hair and nails!
What is Actin
Actin is a protein that makes up microfilaments and thin filaments in myofibrils. It is the most abundant protein in eukaryotic cells. Actin proteins have a positive side and a negative side, which allows motor proteins to travel unidirectionally along an actin filament, like a one way street. involved in cell migration
What does tubulin make and what are the 3 functions of the structure that it makes
Tubulin is the protein that makes up microtubules. MIcrotubules are important for providing structure, chromosome separation in mitosis and meiosis, and intracellular transport with kinesin and dynein. Tubulin, like actin, has polarity: The negative end is usally closer to the nucleus and the positive end is usually in the periphery of a cell.
What is the role of motor proteins?
Motor proteins are proteins responsible for muscle contraction, cellular movement and movement of vessicles. The motor proteins act as ATPases, which means they use ATP to power the conformational changes associated necessary for motor function. Motor proteins interact with microtubules and actin filaments to exert their effects.
What is myosin
Myosin is the primary motor protein that interacts with actin. Myosin also acts as the thick filament in a myofibril. Canbe involved in cellular transport.
What is Kinesin?
Kinesin is one of the two motor proteins that associates with microtubules. Kinesin plays a key role in aligning chromosomes during metaphase and depolymerizing microtubules during anaphase. Kinesin also transports cargo vesicles towards the positive end of the microtubule.
What is Dynein?
Dynein is one of the two motor proteins that interacts with microtubules. Dyneins are involved in the sliding movement of cilia and flagella. Dynein also transports cargo vesicles towards the negative end of the microtubule.
What are binding proteins?
Binding proteins are proteins with special affinity for a specific molecule of interest to provide stabilization. They are usually used to wrap up or transport things. For example, hemoglobin is a binding protein for oxygen. There are also calcium binding proteins, DNA binding proteins, and others. Sequestration=high affinity, transport=varying affinity (needs to bind and let go). calcium and magnesium commonly bound
What are cell adhesion molecules and what are the three types?
Cell adhesion molecules (CAMs) are proteins found on the surface of most cells and aid in binding the cell to the extracellular matrix or other cells. All CAMs are integral membrane proteins.
- Cadhedrins
- Integrins
- Selectins
What are cadhedrins?
Cadhedrins are a group of glycoproteins that mediate calcium dependent cell adhesion. Cadhedrins usually hold similar cell types together. For example, E-cadhedrin holds epithelial cells while N-cadhedrin holds nerve cells together.
What are Integrins?
Integrins are a group of proteins that have two membrane spanning chains referred to as alpha and beta. These chains are important in binding to and communicating with the extracellular matrix. Also, integrins play an important role in cellular signaling, and thus can greatly impact cellular function affecting cell division or apoptosis. Finally, integrins help white blood cells migrate and attach to cells.
What are Selectins?
Selectins are unique in that they bind to carbohydrate molecules that project from other cell surfaces. Selectin bonds are the weakest bonds found in Cell Adhesion Molecules. Selectins are expressed on white blood cells and endothelial cells. They play an important role in inflammation and white blood cell migration, like integrins.
What is an antibody?
An antibody, aka immunoglobulin, is a protein produced by B-cells that functions to neutralize immune system targets and then recruit other cells to help eliminate the threat.
What are the three possible outcomes when an antibody binds to an antigen?
- The antigen is neutralized, making the pathogen or toxin unable to exert its effect on the body.
- Marking the pathogen for destruction by other white blood cells, this marking function is also called opsonization.
- Clumping together (agglutinating) the antigen and antibody into large insoluble protein complexes that can then be phagoctyized and digested by macrophages.
What is Biosignaling and what are three main types of proteins responsible for it?
Biosignaling is a process in which cells receive and act on signals.
- Ion Channels
- Enzyme Linked Receptors
- G-Protein Coupled Receptors
What are ion channels and what are the three types?
Ion channels are proteins that create specific pathways for charged molecules. Ion channels can have different mechanisms for opening and closing, but they all permit facilitated diffusion of charged particles.
- Ungated Channels
- Voltage Gated Channels
- Ligand Gated Channels
