FUNCTIONS OF CARBOHYDRATES

 

 

• Carbohydrates spare protein so that protein can concentrate on building, repairing, and maintaining body tissues instead of being used up as an energy source.
• For fat to be metabolized properly, carbohydrates must be present. If there are not enough carbohydrates, then large amounts of fat are used for energy. The body is not able to handle this large amount so quickly, so it accumulates ketone bodies, which make the body acidic. This causes a condition called ketosis.
• Carbohydrate is necessary for the regulation of nerve tissue and is the ONLY source of energy for the brain.
• Certain types of carbohydrates encourage the growth of healthy bacteria in the intestines for digestion.
• Some carbohydrates are high in fibre, which helps prevent constipation and lowers the risk for certain diseases such as cancer, heart disease and diabetes.

 

CARBOHYDRATES

A carbohydrate is an organic compound that consists only of carbon, hydrogen, and oxygen, usually with a hydrogen:oxygen atom ratio of 2:1 (as in water); in other words, with the empirical formula Cm(H2O)n. (Some exceptions exist; for example, deoxyribose, a component of DNA, has the empirical formula C5H10O4.) Carbohydrates are not technically hydrates of carbon. Structurally it is more accurate to view them as polyhydroxy aldehydes and ketones.

	Eukaryotic Cell	Prokaryotic Cell
Nucleus:	Present	Absent
Number of chromosomes:	More than one	One–but not true chromosome: Plasmids
Cell Type:	Multicellular	Unicellular
True Membrane bound Nucleus:	Present	Absent
Example:	Animals and Plants	Bacteria and Archaea
Telomeres:	Present (Linear DNA)	Circular DNA doesn’t need telemeres
Genetic Recombination:	Mitosis and fusion of gametes	Partial, undirectional transfers DNA
Lysosomes and peroxisomes:	Present	Absent
Microtubules:	Present	Absent or rare
Endoplasmic reticulum:	Present	Absent
Mitochondria:	Present	Absent
Cytoskeleton:	Present	May be absent
DNA wrapping on proteins.:	Yes	No
Ribosomes:	larger	smaller
Vesicles:	Present	Present
Golgi apparatus:	Present	Absent
Mitosis:	Yes	No—but has binary fission
Chloroplasts:	Present (in plants)	Absent; chlorophyll scattered in the cytoplasm
Flagella:	Microscopic in size; membrane bound; usually arranged as nine doublets surrounding two singlets	Submicroscopic in size, composed of only one fiber
Permeability of Nuclear Membrane:	Selective	not present
Plasma membrane with steriod:	Yes	Usually no
Cell wall:	Only in plant cells (chemically simpler)	Usually chemically complexed
Vacuoles:	Present	Present
Cell size:	10-100um	1-10um

TEST YOURSELF 
DEFINE THE FOLLOWING:
Cell membrane
Rough ER
Golgi body
Ribosomes
Mitochondrion
Nuclear membrane
Cytoplasm
Ribosome
Centrosome
Nucleus
Smooth ER
Vacuole
Chloroplast
Lysosomes
Cell wall
Amypoplast

THE CELL

http://http://www.youtube.com/watch?v=MD5kvqO96OsCELL INTRODUCTION
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing (except virus, which consists only from DNA/RNA covered by protein and lipids), and is often called the building block of life.Organisms can be classified as unicellular (consisting of a single cell; including most bacteria) or multicellular (including plants and animals). Humans contain about 100 trillion (1014) cells. Most plant and animal cells are between 1 and 100 µm and therefore are visible only under the microscope.

CELLS AND CELL DIVISION RESEARCH SUMMARY
Cells multiply by cell division. The dividing cells passes through a cell cycle consisting of interphase and divisional phase. Interphase include the DNA synthetic phase.
Somatic cells divide by mitosis. Mitosis includes both nuclear division and or cytoplasm (cytokinesis). During karyokinesis the chromosome become free due to membrane disintegration. Mitotic spindle is formed and the chromosome remain at the equator. Each chromosome splits into a pair of chromatids which are joined at the centromere. Subsequently, the two chromatids separate from one another and pass to opposite poles and become chromosomes of daughter cells.
Mitosis is a fundamental process for life. During mitosis, a cell duplicates all of its contents, including its chromosomes, and splits to form two identical daughter cells. Because this process is so critical, the steps of mitosis are carefully controlled by a number of genes. When mitosis is not regulated correctly, health problems such as cancer can result.

The other type of cell division, meiosis, ensures that humans have the same number of chromosomes in each generation. It is a two-step process that reduces the chromosome number by half—from 46 to 23—to form sperm and egg cells. When the sperm and egg cells unite at conception, each contributes 23 chromosomes so the resulting embryo will have the usual 46. Meiosis also allows genetic variation through a process of DNA shuffling while the cells are dividing.