Chapter 7: Carbohydrates Flashcards
What is the name of a signal cell surface acid that was recently found in some cancer cells, thereby protecting it from the attack of our immune system? Give the common and IUPAC name.
Sialic acid (N-acetylneumaraminic acid)
What is the function of sialic acid into our cell?
-Sialic acids contribute to cell recognition, allowing cells to identify and interact with each other.
-They can act as “self-markers” that help the immune system distinguish between “self” and “non-self” cells.
how do green plants produce carbohydrates? Give the reaction equation.
via photosynthesis (CO2 + H2O + solar energy –(chlorophyll (plant enzymes)—> carbohydrates + O2
two main uses of carbohydrates in plants
- In the form of glucose - serves as structural elements
- In the form of starch - they provide energy reserves
6 functions of carbohydrates in humans.
- Carbohydrate oxidation provides energy
- In the form of glycogen, provides short term energy reserves
- supply carbon atoms for the synthesis of other biochemical substances
- essential components in the mechanisms of genetic control of growth and development of living cells
- linked in lipids: structural components in cell membranes
6: linked in proteins: function in a variety of cell-cell or cell-molecule recognition processes.
general formula of carbohydrates
CnH2nOn or Cn(H2O)n
what is carbohydrate?
- is a polyhydroxy aldehyde or polyhydroxy ketone, or a compound that yields polyhydroxy aldehyde or polyhydroxy ketone upon hydrolysis.
types of carbohydrates based on molecular size.
- monosaccharides
- disaccharides
- oligosaccharides
- polysaccharides
a carbohydrate that contains single polyhydroxy aldehyde or polyhydroxy ketone
monosaccharides
a carbohydrate that contains two monosaccharides unit (lactose and sucrose are one of examples)
disaccharides
a carbohydrates that contains 3-10 monosaccharides covalently bonded to each other
oligosaccharides
a polymeric carbohydrates that contains many monosaccharides unit
polysaccharides
the complete hydrolysis of disaccharides, oligosaccharides, and polysaccharides produces what?
monosaccharides
what do you call on a carbon atom that has four different groups bonded to it
chiral carbon
chiral molecules are what kind of stereoisomers?
enantiomers
3 different response of D and L chiral forms
- a. sometimes both forms are biologically active, each form giving a different response
b. both elicit the same response but one’s form is many times greater than the others;
c, only one of the two forms is biochemically active
a compound that rotates the plane of polarized light
optically active compound
a chiral compound that rotates the plane of polarized light in a clockwise direction
dextrorotatory compound
a chiral compound that rotates the plane of polarized light in a counterclockwise
levorotatory compound
why do enantiomers have identical boiling points, melting points, and densisties?
because such properties depend on the strength of intermolecular forces, and these intermolecular forces does not depend on chirality. Intermolecular force strength is the same for both forms of a chiral molecule because both forms have identical sets of functional groups
classification of monosaccharides based on the type of carbonyl group.
- aldose
- ketose
a monosaccharide that contains aldehyde functional gruop
aldose
a monosaccharide that contains a ketone functional group
ketose
