Carbohydrates and Lipids Quiz

Study Notes

Composed of carbon, hydrogen, and oxygen in a ratio of roughly 1:2:1.
Common examples include glucose, fructose, and sucrose.
Play essential roles in energy storage, providing immediate energy for cells, and cellular recognition.

Comprised mainly of carbon and hydrogen with a lower proportion of oxygen compared to carbohydrates.
Examples include triglycerides, phospholipids, and steroids.
Function in energy storage, forming cell membranes, and signaling molecules.

Saccharides are sugar molecules categorized into monosaccharides, disaccharides, oligosaccharides, and polysaccharides.
Monosaccharides are the simplest form of carbohydrates, consisting of single sugar units like glucose.
They are classified based on the number of carbon atoms: triose (3), pentose (5), hexose (6).
Glucose is a hexose monosaccharide.
Aldose examples include glucose and galactose; ketose examples include fructose.

Ring conformations allow monosaccharides to easily participate in biochemical reactions.
Disaccharides consist of two monosaccharide units linked by glycosidic bonds.
Maltose forms from two glucose units, while sucrose consists of glucose and fructose.
Enzymes maltase and sucrase hydrolyze these disaccharides; humans possess these enzymes.
Enzymes typically have the suffix "-ase".

Polysaccharides are large carbohydrate molecules made of long chains of monosaccharides.
Plants synthesize starch for energy storage and cellulose for structural support.
Humans can digest starch using amylase, but lack cellulase to digest cellulose.
Cellulose aids digestive health by adding bulk to stool.

Glycogen is a storage form of glucose in animals, constructed from branched chains of glucose units.
Synthesized primarily by liver and muscle cells.
Favorable conditions for glycogen synthesis occur when glucose levels are high after meals, while low glucose levels stimulate breakdown.
Excess glucose beyond glycogen storage is converted to fat.

Fatty acids are hydrocarbon chains with a carboxylic acid functional group.
They vary in length and degree of saturation (number of double bonds).
Glycerol is a three-carbon alcohol that forms the backbone of triglycerides.
Triglycerides consist of three fatty acids connected to glycerol; the fatty acids do not need to be of the same length.
Adipocytes are cells that both synthesize and store triglycerides, which are crucial for energy storage.
Overconsumption of triglycerides can lead to obesity and associated health issues.

Fats are classified as saturated (no double bonds) or unsaturated (one or more double bonds).
Saturated fatty acids tend to be solid at room temperature due to tight packing, while unsaturated fatty acids are liquid.
Categories include polyunsaturated fats (multiple double bonds), monounsaturated fats (one double bond), trans fats (hydrogenated oils), and saturated fats (no double bonds).
A cis double bond creates a kink in the fatty acid chain, affecting fluidity; trans double bonds do not create such a kink, resembling saturated fats.
LDL-C (Low-Density Lipoprotein Cholesterol) is associated with cholesterol deposition in arteries, whereas HDL-C (High-Density Lipoprotein Cholesterol) is involved in cholesterol removal from circulation.