Cell Biology Chapter 3 Sugars and Lipids Flashcards
Polymers are synthesized by what? Most biological macromolecules in cells are synthesized from what?
by condensation reactions in which activated monomers are linked together by the removal of water; from about 30 common small molecules
What are polysaccharides? What are monosaccharides? What purpose do they serve? What are oligosaccharides?
long chain polymers of sugar and sugar derivates; repeating units of polysaccharides; serve primarily in structure and storage; short polymers that are sometimes attached to cell surface?
What is the single most common monosaccharide? In the cell what exists and where?
the hexose d-glucose; d-glucose exists in a dynamic equillibrium between the linear and ring form
Where does glucose exist? What is the linkage of disaccharides?
in disaccharides in which 2 monosaccharides units are covalently linked; glycosidic bond formed between 2 monosaccharides by the elimination of water
What can polysaccharides do? What are the most familiar storages of polysaccharides?
Can be stored and can provide structure; starch in plant cells and glycogen in animal cells and bacteria
Where is glycogen mainly stored?
mainly stored in the liver as a source of glucose, stored in the muscle tissues as fuel source for muscle contractions of animals; bacteria store glycogen as a glucose reserve
What is starch and what is it stored as?
Starch is the glucose reserve commonly found in plant tissue; stored as starch grains within the plastids
What is cellulose best known as and where is it found? What can’t mammals digest?
best known as structural polysaccharide is found in plant walls; can’t digest cellulose though some have microorganisms in their digestive systems that can
Bacterial cell walls contain what two kinds of sugar? Where is chitin found?
GlcNAc and MurNAc; found in insect exoskeletons, crustacean shells, and fungal cell walls
Lipids are not formed by the same type of what? How are they viewed and why?
of linear polymerization that forms proteins, nucleic acids, and polysaccharides; viewed as macromolecules because of their high molecular weight and their importance in cellular structures, particularly membranes
All lipids have what type of nature and little what? Lipids are soluble in what?
Hydrophobic nature, heterogenous and little affinity for water; soluble in nonpolar solvents such as chloroform or ether
Some lipids are what? What are their functions?
amphipathic, having polar and nonpolar regions; functions include: energy storage, membrane structure, specific biological functions, signal transmission
Lipids are divided based on what and examples?
based on their structure; fatty acids, triacylglycerols, phospholipids, glycolipids, steroids
Fatty acids are components of what? Describe fatty acids
of several other kinds of lipids; long amphipathic unbranched hydrocarbon chain with a carboxyl group at one end
The polar carboxyl group is the what and the nonpolar hydrocarbon chain is the what? Fatty acids yield what? What is saturated fatty acids?
the head and the tail; large amount of energy when broken down; each carbon atom in the chain is bonded to the maximum number of hydrogens
Unsaturated fatty acids definition, Trans fat definition; What have they been linked to ?
have one or more double bonds so they have bends in the chains and are less tightly packed; type of unsaturated fatty acid with a particular type of double bond that causes less of a bend in the chain; linked to increased risk of heart disease and elevated cholesterol levels
What is the main function of triacylglycerols? What do they contain and where are they found?
energy storage; mostly saturated fats are usually solid or semisolid at room temperature- fats; found in plants and are liquid at room temperature
What are phospholipids important to what and why? How can they be divided?
important to membrane structure because of their amphipathic nature; divided into phosphoglycerides and sphingolipids
Phosphoglycerides are what in most membranes? The length and degree of saturation of the fatty acids have what?
the predominant phospholipids; have profound effects on membrane fluidity
Sphingolipids are predominantly found where; What are important in communication and between what; Sphigolipids have a what and are believed to protect what?
in the outer leaflet of the plasma membrane bilayer often in lipid rafts - localized domains within a membrane; lipid rafts in communication between a cell and its external environment; structural function and are believed to protect the cell surface from harmful environmental factors
What are glycolipids? Where do they occur?
Lipids containing a carbohydrate instead of a phospholipid; occur largely on the outer monolayer of the plasma membrane
Steroids are derivaties of what? Most common steroid in animal cells?
four-ringed hydrocarbon skeleton which distinguishes them from other lipids; cholesterol
Cholesterol is what and found where? Cholesterol is the starting material for synthesis of what? Similar molecules are found where?
insoluble and found primarily in plasma membranes of animal cells and most membranes of organelles; steroid hormones including male and female sex hormones, the glucocorticoids, and mineralocorticoids; plant and fungal cells
Sex hormones include what?
estrogens produced by the ovaries of females and androgens produced by male testes
Glucocorticoids are a family of what?
hormones that promote synthesis of glucose and suppress inflammation
Mineralocorticoids regulate what and how?
ion balance by promoting reabsorption of sodium, chloride, and bicarbonate ions by the kidney
