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Endocytosis -Types and Phagocytosis

By: HWC, Views: 6697

Endocytosis is the process by which a substance is brought inside a cell without having to pass through the cell membrane. It is the opposite of endocytosis, the process by which substances exit the cell without having to pass through the cell membrane. Exocytosis – membrane-enclosed secret...

Oxygen - hemoglobin dissociation curve & Hemoglobin's affinity with oxygen - acidity

By: HWC, Views: 7310

• The partial pressure of oxygen is a primary factor influencing the degree of saturation of hemoglobin. • The Po2 determines the number of oxygen molecules that can bind or dissociate from hemoglobin. • Blood in vessels coming from the lungs is very high in Po2 so saturation is high. ...

Phases of mitosis

By: HWC, Views: 4648

Prophase is the first step in the mitotic process. During prophase, the chromosomes condense. The centrosomes begin to form a spindle and move into position on opposite sides of the cell. Sister chromatids are held together by a protein called cohesin at the centromere. Prometaphase is the sec...

B cells and antibodies

By: HWC, Views: 7482

What Are Antibodies? Antibodies, also known as immunoglobulins, are Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body. When an intruder enters the body, the immune system springs into action. These invaders, which are called antigens, can be vi...

Embryonic development - Week 3

By: HWC, Views: 6712

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...

DNA Replication

By: HWC, Views: 3510

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.

Stomach peristalsis - Movement of Food Through the Small Intestine

By: HWC, Views: 6689

Peristalsis is a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract. The process of peristalsis begins in the esophagus when a bolus of food is swallowed. The strong wave-like motions of the smooth muscle in the esophagus carry the food...

Hip and Thigh Movement Animation

By: Administrator, Views: 312

- The 3 hamstring muscles (biceps femoris, semimembranosus and semitendinosus) – these muscles form most of the flesh of the back of the thigh; they flex the knee and extend the hip; - Gluteus maximus muscle (buttock); and, - Gracilis, sartorius and plantaris muscles.

Origin of organelles Animation

By: HWC, Views: 305

Possible origins of the nucleus and other organelles. Some prokaryotic cells have infoldings of their plasma membrane. These infoldings may have served as channels from the cytoplasm to the cell surface. These membranous folds may have evolved into the endoplasmic reticulum and the nuclear e...