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Introduction to Photolithography - WC, BLF, PA, Hard and Soft baking

By: HWC, Views: 7339

Prior to use, wafers are chemically cleaned to remove particulate matter on the surface as well as any traces of organic, ionic, and metallic impurities. Barrier Layer Formation After cleaning, the silicon wafer is covered with the material which will serve as a barrier layer. The most commo...

Pores and Ion Channels

By: HWC, Views: 6922

Transmembrane channels, also called membrane channels, are pores within a lipid bilayer. The channels can be formed by protein complexes that run across the membrane or by peptides. They may cross the cell membrane, connecting the cytosol, or cytoplasm, to the extracellular matrix. Membrane po...

The life cycle of protein

By: HWC, Views: 7374

The life cycle of a typical protein begins with its synthesis on a ribosome. As the polypeptide chain grows, molecules of a chaperone protein bind along its length. This prevents misfolding of the nascent polypeptide. ATP binding causes chaperone release. For most proteins, the polypeptide th...

Hormonal regulation of pregnancy - weeks 17 through 38

By: HWC, Views: 7996

• Estrogens increase uterine blood flow, maintaining the endometrium during pregnancy. • High levels of estrogen and progesterone inhibit the synthesis of milk. Progesterone inhibits myometrial contractions of the uterus to prevent premature birth. • Relaxin inhibits myometrial contract...

New DNA Strand Replication

By: HWC, Views: 7142

First step: strands are separated • Helicase unwinds the DNA double helix at the replication fork • SSBs coat the single strands to prevent reannealing • Polymerase attaches nucleotide at 3' end • Synthesis is in 5' to 3' direction DNA Polymerase: • Only extends nucleic ac...

Status Epilepticus

By: Administrator, Views: 10723

Status epilepticus (SE) is a single epileptic seizure lasting more than five minutes or two or more seizures within a five-minute period without the person returning to normal between them. Previous definitions used a 30-minute time limit. The seizures can be of the tonic–clonic type, with a re...

Fermentation - When Oxygen Is Absent, Pyruvate to Lactate & Pyruvate to Ethanol

By: HWC, Views: 7299

Pyruvate is the end product of glycolysis. If oxygen is present, pyruvate enters the mitochondrion where further energy yielding reactions of the Krebs cycle will take place. However, if oxygen is not present, pyruvate will enter a pathway called fermentation. This pathway regenerates NAD+ fro...

Proteins

By: HWC, Views: 6790

Living things must accomplish a great number of tasks just to get through a day, and these tasks are accomplished by a diverse range of biological molecules. In the range of tasks that molecules accomplish, however, proteins reign supreme. Almost every chemical reaction that takes place in living...

Lipid catabolism - lipolysis and beta oxidation and oxidation of fatty acids

By: HWC, Views: 7984

• Digestion hydrolyzes lipids into fatty acids and glycerol. • Fatty acids and glycerol are: • Oxidized to generate ATP. • Used to produce triglycerides that are stored as energy reserves in adipose tissue. • Lipid catabolism begins with lipolysis in which lipids are broken do...