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Male Reproductive System - The gonadotropin releasing hormone

By: HWC, Views: 7378

• Hormonal mechanisms that influence male reproductive function involve endocrine tissues contained in the: • Hypothalamus of the brain. • Anterior pituitary. • Testes. • In the hypothalamus, certain neurosecretory cells secrete gonadotropin- releasing hormone (GnRH). • GnRH ...

Peptide Bond Formation Animation

By: HWC, Views: 505

During protein synthesis, peptide bonds link amino acids together in the order specified by DNA instructions. In this case, the first two amino acids in the protein are methionine and alanine. Here are ball-and-stick models of these amino acids. Peptide bond formation is a type of condensatio...

Exocytosis - secretion

By: HWC, Views: 6646

Exocytosis is another method of vesicular transport that moves large volumes Of fluid or chemicals out of the cell. It is a process by which a cell transports secretory products through the cytoplasm to the plasma membrane. A examples of cellular secretory products: 1. Secreted protein - enzym...

Hydrogen bonds vs. Ionic bond

By: HWC, Views: 5467

The slight positive charge of a hydrogen atom in a water molecule can attract an atom with a slight negative charge, such as the nitrogen in a molecule of ammonia. This forms a hydrogen bond between the two atoms. Hydrogen bonds join the two strands of a DNA molecule. Although hydrogen bo...

Medullary osmotic gradient - influencing factors

By: HWC, Views: 7013

▪ Maintenance of fluid volume and composition, despite changes in water input and output, is crucial to a healthy life. ▪ Regulation of blood's osmolarity, or solute concentration, is a function of the nephron. • Normal osmolarity is maintained by the ability of the nephron to alter uri...

Kinetic parameters & Kinetic experiment

By: HWC, Views: 6506

Kinetics is a measure of the speed or rate of a chemical reaction. A study of kinetics allows us to determine which variables to control (temperature, reactants, catalysts) and how to vary them in order to maximize the amount of products formed and minimize the time involved. Vmax = maximum ve...

Factors that influence muscle tension - Sarcomere length and force, understretched and overstretched

By: HWC, Views: 6668

• Muscle tension generated through the contraction of muscle cells provides the force necessary for the muscular system to function. • The amount of tension produced depends on several factors: • Sarcomere length Frequency of stimulation • Motor unit size • Recruitment of moto...

Neurotransmission at chemical synapses & Excitory and inhibitory potentials

By: HWC, Views: 6574

• A series of events occur at chemical synapses in order to communicate with the adjacent cell. • The action potential arrives at the presynaptic membrane. • The depolarization phase of the action potential opens voltage gated Ca+ channels. • increased inflow of Ca+' into the cyto...

Type of Cell Junctions - Desmosome, Hemidesmosomes and Gap Junctions

By: HWC, Views: 7012

Cell Junctions: Cell junctions are found in some multi-cellular organisms. They exist of complexes and are found between cells and between cells and other structures. The junctions provide a way for cells to connect and exchange signals. What are tight junctions, desmosomes, and gap junctions...