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Gastrulation: cross section of the frog

By: HWC, Views: 5734

Gastrulation Most animals enter a phase early in development called gastrulation. In this phase, a tiny ball or disc of cells rearranges to form three embryonic layers of tissue, called germ layers. The germ layers of the embryo—now called a gastrula—are called the endoderm, mesoderm, and eco...

Role of ATP in muscle movement

By: HWC, Views: 6830

• Muscle cells use ATP to power contraction and movement. • The hydrolysis of ATP to ADP releases • ATP can be regenerated by adding to ADP. • During muscular contraction, ATP molecules: • Energize the myosin head • Detach myosin from actin • ATP must be then regenerat...

Embryonic development - Week 3

By: HWC, Views: 6704

Week 3 (gastrulation) • Three primary germ layers are formed which provide cells for organ formation in the following months. • These germ cell layers are formed by a process known as gastrulation, which involves rearranging epiblast cells. • As cells from the epiblast migrate, a fain...

X chromosome inactivation in calico cats

By: HWC, Views: 3601

X chromosome inactivation causes a mosaic tissue effect in calico cats. what makes this female calico cat "calico." Like all mammals, this cat began her life as a single cell. That cell had two X chromosomes, one from each parent. One of the chromosomes carried a dominant allele for the ...

Central Nervous System Animation

By: Administrator, Views: 9730

Consists of the brain and spinal cord. CNS receives impulses from throughout the body processes the information responds with an appropriate action Brain and spinal cord can be divided into: gray matter (unsheathed cell bodies and true dendrites) white matter (myelinated nerve fibers) ...

Parathyroid hormone (bone resorption) & Calcitonin (bone deposition)

By: HWC, Views: 6673

• Cellular needs for calcium may cause blood calcium concentrations to decline below the normal range. • This decrease stimulates cells in the parathyroid gland to secrete parathyroid hormone. • Binding of parathyroid hormone to osteoclasts in bone tissue promotes bone resorption and th...

How proteins function? How do proteins work?

By: HWC, Views: 6280

How proteins function is really about how proteins "do work" in cells. How do proteins work? Let's start thinking about protein function by looking at something important to you: your hair. Keratin is a structural protein that is composed of 2 intertwined or helical strands. Keratin is also f...

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

By: HWC, Views: 6993

• 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...

Endocrine System Animation

By: Administrator, Views: 1001

Vital function of endocrine system: Production and regulation of chemical substances called hormones. Hormones Chemical transmitters released in small amounts and transported via bloodstream to a target organ or other cells. Transfer information and instructions from one set of cells to anot...