Lecture 4 - Carbohydrates Part 1 Flashcards
What are the 3 atoms found in a carbohydrate?
C, H, O
What is the main function of carbohydrates in a cell/our body?
primary energy source for metabolic processes
What are monosaccharides?
simple sugars
-number of carbon atoms (pentose or hexose)
-defined by type of carbonyl group (aldose or ketose)
What are D-glucose and L-glucose?
D-sugars: OH group right of chiral center
L-sugars: OH group left of chiral center
What is the natural form of glucose (D or L)?
L-glucose = natural form
What is the pyranose form of sugar?
-OH group on 5’ carbon
Is the dominating form of D-glucose the open chain form or furanose form?
furanose form = dominant
ring is more thermodynamically stable
What kind of sugar is lactose?
disaccharide
galactose + glucose
joined by glycosidic bond
What is an anomer?
C1 = anomeric carbon
geometric variation of cyclic sugars
alpha and beta carbons on either side
What kind of covalent bond is formed between 2 sugar molecules?
glycosidic bond
Which of the 4 major biomolecules contains ribose, nitrogenous base, and a phosphate?
nucleic acids
nucleotide = nitrogenous base glycosidic bond to ribose sugar
nucleotide = nucleoside covalently bound to phosphate group
In which important molecule do we find a ribose, nitrogenous base adenine, and 3 phosphate groups attached?
ATP
What kind of sugar is glycogen?
polysaccharide
short-term energy storage
What are examples of disaccharide?
lactose
sucrose
fructose
What is starch and the 2 components it consists of?
starch: polymeric carbohydrate (many glucose units joined by glycosidic bonds)
produced by green plants for energy storage
amylose + amylopectin
What is the major function of glycogen?
short term energy storage
Where in the body is glycogen primarily stored?
liver and skeletal muscle
What are glycosaminoglycans?
structural carbohydrates
mucopolysaccharides - viscous, lubricating properties
part of proteoglycans
negatively charged
repeating 2-sugar unit = uronic sugar + amino sugar
What are the functions of GAGs?
regulation of cell growth
proliferation
promotion of adhesion
anticoagulation
repair
What is an example of GAG?
keratin sulfate in cornea
What is proteoglycan made of?
heavily glycosylated proteins
baseic proteoglycan unit = “core protein” + 1 or more covalently attached GAG
serine = point of attachment
in connective tissue
Which proteoglycan is the major PG in the cornea?
keratin sulfate
What are glycoproteins?
proteins that have oligosaccharide chains (glycans) bound to polypeptide chain
What is glycosylation?
co-trnaslational or posttranslational modification (after peptide chain is made)
What are the 2 most common types of glycosylation?
N-glycosylation: sugars attached to nitrogen
O-glycosylation: sugars attached to oxygen
What is glypiation?
form of glycosylation resulting in creating a membrane anchor
