Carbs, Nucleic Acids, Lipids (11-13) Flashcards
UMN Biochemistry Midterm 2 Part. 1
The definition of a carbohydrate, what are the basic structural components
3-7 carbon chain, with many hydroxyl groups (OH), and one aldehyde or ketone (polyhydroxy aldehyde or ketone)
Carb formula
Cn(H2O)n
Quiz Q: A carbohydrate may be defined as a molecule
that is an aldehyde or ketone that has more than one hydroxyl group source
Monosaccharide
Monosaccharide = single sugar, 3-7 C in length
Can form stereoisomers
Can be alpha or beta
Can be cyclic
Can be alpha or beta
Disaccharide
Disaccharide = 2 sugars linked by glycosidic bond
Polysaccharide
Polysaccharide = many sugars (>10) linked together
Relating to -saccharides: Glycosidic bond
hemiacetal and alcohol
Can be alpha or beta
(A hemiacetal is an alcohol and ether ATTACHED TO THE SAME CARBON.)
ID Aldehyde Functional Group
H-C=O
ID Ketone Functional Group
R-C-H
=O
ID isomers of Glucose that we should know for the exam
Alpha and Beta D glucose
Can someone lmk what other ones i should be able to ID
STARCH- polysaccharides
alpha D-glucose and alpha 1,4 link (OH down)
Storage
Forms helical coils / spherical particles
GLYCOGEN -polysaccharides
Alpha D-glucose and alpha 1,4 link (OH down)
Storage
More highly branched than starch
CELLULOSE -polysaccharide
Beta D-glucose and B 1,4 link (OH up)
Structural
Forms bundles - intra and interstrand hydrogen bonds
Composed of 1000s of glucose units that that due to the beta linkage can from extensive intrastrand
Interstrand hydrogen bonds
Stereoisomers
Physical properties same
Differ in way they end polarized light
Don’t interact with same binding sites on enzymes/proteins
Stereoisomeric forms because of chiral centers - carbon atom bonded to 4 different groups
Same chemical formula, different arrangements
Nonsuperimposable mirror images
Configuration about the chiral center furthest from the aldehyde or ketone determines if its in D or L configuration (most in D)
Cyclization
Monosaccharides with 5-6 carbons atoms exist in cyclic form - form internal bond between carbonyl group and hydroxyl group (hemiacetal bond)
The type of bond formed between monosaccharides in disaccharides and polysaccharides, how can they differ? And how can this affect the structure and properties of a polysaccharide
Glycosidic bond - hemiacetal + alcohol
Links monosaccharides to form disaccharides or polysaccharides
Can be alpha or beta configuration
Once bond formed, configuration is locked and results in different properties of the products
DNA role
store genetic info (ATGC)
DNA
Release genetic info
mRNA, TRNA, rRNA
DNA Intermediates in metabolism
NAD+/NADH - redox coenzymes
ATP - energy storage
Signaling molecules DNA
cAMP, cGMP
Sugar
DNA VS RNA
D-ribose (RNA)
2-deoxyribose (DNA) (missing oxygen for carbon #2)
Bases
DNA VS RNA
RNA: Adenine, Uracil, Cytosine, Guanine
DNA: Adenine, Thymine, Cytosine, Guanine