Search Results

Requirements for nervous signals

By: HWC, Views: 8907

• The function of neurons is to allow communication between cells, thereby maintaining homeostasis. • Electrical signals, called membrane potentials, travel along the membranes of the neurons. • Voltage variability and distance traveled determine the type of nervous signal. 1. Graded...

Olfaction. or the sense of smell

By: HWC, Views: 6420

Do you ever wonder how you can distinguish thousands of different odors? Olfaction. or the sense of smell, is used by all mammals to navigate, find food, and even find mates. We have millions of olfactory receptors for smelling in our nose. These receptor neurons bind water-soluble or volatil...

Lipid catabolism ( ketogenesis and oxidation of glycerol) and Lipid anabolism (lipogenesis)

By: HWC, Views: 9270

• During excessive beta oxidation, the two-carbon fatty acid fragments are converted into acidic ketone bodies. • Ketosis, the overproduction of ketone bodies, can lead to acidosis (ketoacidosis) of the blood. • After lipolysis, glycerol is converted to pyruvic acid. • Pyruvic aci...

Type of Transport - Active and Passive Processes

By: HWC, Views: 9249

Active transport moves materials from lower to a higher concentration, while passive transport moves materials from higher to lower concentration. Active transport requires energy to proceed, while passive transport does not require the input of extra energy to occur. Transport processes that ...

Complement Proteins Animation

By: HWC, Views: 5757

Formation of membrane attack complexes. Complement proteins can activate when they bind to antibodies that are bound to a pathogen. Complement proteins also activate when they bind directly to bacterial surfaces. Cascading reactions yield huge numbers of different types of complement protei...

Nucleic acid digestion - brush border enzymes, end products & transport mechanism

By: HWC, Views: 8746

• Further digestion occurs at the microvilli (brush border) of the epithelial cells of the villi in the small intestine. • Two brush border enzymes complete nucleic acid digestion: • Phosphatases, which catalyze the cleavage of a phosphate to form a nucleoside (nitrogenous base and pent...

Fertilization and Development

By: HWC, Views: 9307

• Fertilization is the process by which the two gametes from the parents fuse their genetic material to form a new individual (zygote). • Fertilization requires that sperm cells swimming through the uterine tube contact a secondary oocyte. • Once sperm penetrate the secondary oocyte's ...

Protein catabolism (Krebs cycle) and Protein anabolism (protein synthesis)

By: HWC, Views: 9483

• Deaminated acids are brought into the Krebs cycle to be oxidized to CO2 and H2O. • Before entering the Krebs cycle, the deaminated acids are converted into intermediate products (pyruvic acid, acetyl coenzyme A, carbonic acids). • In the Krebs cycle, amino acids are oxidized to form r...

HDL (high density lipoprotein)

By: HWC, Views: 7876

HDL cholesterol can be thought of as the “good” cholesterol. (So, in the case of HDL cholesterol, higher levels are actually better.) The body uses cholesterol to make hormones and vitamin D and to support digestion. HDL carries LDL (bad) cholesterol away from the arteries and back to t...