TERMS Flashcards
Metaphase
a stage of mitosis in the eukaryotic cell cycle in which chromosomes are at their second-most condensed and coiled stage (they are at their most condensed in anaphase).
Chromatin
A complex of DNA and histone proteins that form the chromosomes. (Long strand of DNA wrapped around nucleosides like a string of beads)
Facilitated Diffusion
When a molecule moves from a high concentration to low concentration. No ATP needed, membrane protein required, specificity of molecules.
Rough Endoplasmic Reticulum (RER)
part of the endomembrane system of the cell and a subset of the endoplasmic reticulum (ER). This organelle is primarily concerned with the synthesis, folding and modification of proteins, especially those that need to be delivered to different organelles within the cell, or secreted from the cell. The rough ER is also involved in the response of the cell to unfolded proteins and plays a role in the induction of apoptosis, due to its close interaction with mitochondria.
Contiguous
sharing a common border; touching.
Lamellipodia
a cytoskeletal protein actin projection on the leading edge of the cell. It contains a quasi-two-dimensional actin mesh; the whole structure propels the cell across a substrate.
Kinase Signaling
(form of cytoplasmic signaling) are enzymes that alter the activity, expression, or localization of proteins by altering their phosphorylation. Signaling kinases are located in both the cytoplasm and membranes. They can target different amino acids for phosphorylation, including serine, threonine, or tyrosine.
Cohesin
a protein complex that mediates sister chromatid cohesion, homologous recombination and DNA looping. Cohesin is formed of SMC3, SMC1, SCC1 and SCC3 (SA1 or SA2 in humans).
Polypeptide
a linear organic polymer consisting of a large number of amino-acid residues bonded together in a chain, forming part of (or the whole of) a protein molecule.
Paracrine Communication
a form of cell signaling or cell-to-cell communication in which a cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells.
Channel Protein
(Type of integral protein) A channel protein is a special arrangement of amino acids which embeds in the cell membrane, providing a hydrophilic passageway for water and small, polar ions. Like all transport proteins, each channel protein has a size and shape which excludes all but the most specific molecules. No energy needed. Goes with the concentration gradient.
Transmembrane Protein
type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane.
Prophase
the first stage of cell division, before metaphase, during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears. The first prophase of meiosis includes the reduction division.
Histones
highly basic proteins found in eukaryotic cell nuclei that pack and order the DNA into structural units called nucleosomes. Histones are abundant in lysine and arginine.
Calcium Signaling
(form of cytoplasmic signaling) the use of calcium ions (Ca2+) to communicate and drive intracellular processes often as a step in signal transduction. Ca2+ is important for cellular signaling, for once it enters the cytosol of the cytoplasm it exerts allosteric regulatory effects on many enzymes and proteins.
Peripheral Protein
Peripheral membrane proteins are found on the outside and inside surfaces of membranes, attached either to integral proteins or to phospholipids. Unlike integral membrane proteins, peripheral membrane proteins do not stick into the hydrophobic core of the membrane, and they tend to be more loosely attached.
Heterotrimeric G Protein
are the molecular switches that turn on intracellular signaling cascades in response to the activation of G-protein-coupled receptors (GPCRs) by extracellular stimuli. Therefore, G proteins have a crucial role in defining the specificity and temporal characteristics of the cellular response.
Anaphase
the stage of meiotic or mitotic cell division in which the chromosomes move away from one another to opposite poles of the spindle.
Smooth Endoplasmic Reticulum
a membranous organelle found in most eukaryotic cells. Its main functions are the synthesis of lipids, steroid hormones, the detoxification of harmful metabolic byproducts and the storage and metabolism of calcium ions within the cell.
Diffusion Through Channel
When a molecule moves from a high concentration to low concentration. No ATP needed, membrane (gated) protein required, specificity of molecules.
Adenylyl Cyclase
the enzyme that synthesizes cyclic adenosine monophosphate or cyclic AMP from adenosine triphosphate (ATP). Cyclic AMP functions as a second messenger to relay extracellular signals to intracellular effectors, particularly protein kinase A.
Juxtacrine Communication
is a type of cell–cell or cell–extracellular matrix signaling in multicellular organisms that requires close contact.
Microtubules
polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can grow as long as 50 micrometres and are highly dynamic.
Kinetochore
a complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach.