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diffusion
diffusion f

Spread . The particles move from an area of ​​high concentration to an area of ​​lower concentration until the two concentrations become equal. Diffusion occurs when two different concentrations of particles are next to each other.

Direction of particle movement
Low particle concentration
High concentration of particles

The concentration difference that causes diffusion is called the concentration gradient. The greater the concentration gradient, the greater the diffusion rate. If there is no concentration gradient, no diffusion occurs, and this state is called equilibrium.

No concentration gradient (equilibrium)
No spread

Low concentration gradient
Slow spread

High concentration gradation
Rapid spread

Diffusion is the way in which many substances enter and leave living organisms and are transferred within and between cells. For example: (1) Plants take water from the soil. (2) Gas exchange between plants and the atmosphere. (3) Gas exchange between blood and respiratory cells.

Where diffusion is too slow for a particular function, materials can move more quickly by active transport. For a specific case of spread, see osmosis.


digestion
digestion f

Digest. Breaking down large insoluble food particles into small soluble particles by enzyme action before absorption and assimilation. Digestion and absorption occur in the alimentary canal in many animals, including mammals. See the following table and the following figure.

Digestive enzymes in humans

The alimentary canal in humans

Epiglottis - with me esophagus. The sphincter of the heart. Stomach Pyloric sphincter Large pancreas {colon. The rectum. Anus Teeth Tongue Salivary gland Gallbladder Bile duct Kidney - Pancreatic duct Duodenum Minute intestine Final intestine Cecum Appendix)


diploid
diploide

Binary formula. A description of a nucleus, cell, or organism in which the complete complement of chromosomes are homologous pairs. All animal cells are diploid with the exception of gametes, since gametes contain half the number of diploids (haploids) as a result of meiosis. See chromosome, fertilization, haploid, and mitosis.


disaccharides
disaccharides fpl


Disaccharides are double-saccharide carbohydrates consisting of two monosaccharides linked together by bonds. For example: maltose (barley sugar) consists of two glucose units linked together, while sucrose (table sugar) consists of one glucose unit linked to a fructose unit.

Disaccharide structure


division
group f

Department unit used in classification of plants. It is equivalent to the term phylum used in classifying animals. A section and division consist of one or more rows.