Lecture 4 Flashcards
review
What is a macromolecule?
large molecules composed of thousands of covalently connected atoms
review
what is a polymer?
long molecule consisting of many similar building blocks linked by covalent bonds.
- building blocks are called monomers
review
out of the 4 classes of life’s organic molecules ( macromolecules) which 3 contain polymers?
nucleic acid
proteins
carbohydrates
what is the main functions of carbohydrates?
- short term and intermediate energy storage ( starch from plants and glycogen from animals)
- structural components in cells ( cellulose in the cell wall of plants, protists + chitin in the cell walls of fungi and exoskeleton of arthropods )
what is the ratio of carbon, hydrogen and oxygen in carbohydrates?
1:2:1 ratio
what is the organic compound of carbohydrates?
aldehyde or ketone compounds with multiple hydroxyl groups
what do carbohydrates consist of?
monosaccharides
disaccharides
polysaccharides
name three monosaccharides and what are their functions?
1) glucose
2) fructose
3) galactose
Functions: polymer synthesis, component of table sugar and milk sugar
what is used in RNA nucleotides?
ribose - component of RNA
What used in DNA nucleotides?
Deoxyribose - component of DNA
name three disaccharides and their funtions
1) maltose ( glu + glu)
2) lactose ( glu + gal )
3) sucrose ( glu + fru )
Funtions: in plants, table sugar, milk sugar and brewing sugar
name five polysaccharides and name their functions
1) starch
2) glycogen
3) cellulose
4) chitin
5) peptidoglycan
Function: storage in plants, storage in animals, structure in plants + animals + fungi + bacteria
what are the two types of sugar?
aldoses and Ketoses
what is the difference between aldoses and ketoses?
the location of the carbonyl group
what is the carbohydrate of aldoses?
glucose
what is the carbohydrate of ketoses?
fructose
what is the ratio of monosaccharides?
1:2:1 ( carbon, hydrogen, oxygen )
what are the three most common sugars?
1) trioses ( 3 carbons, smallest sugars)
2) pentoses ( 5 carbons, in DNA )
3) Hexoses ( 6 carbons, common sugars)
what is the monosaccharide that is most common in sugars?
hexoses
glucose, galactose, fructose
name each monosaccharide
1) glucose
2) galactose
3) fructose
which one is aldose and which is ketose?
right= ketose
left= aldose
what is the most common monosacharride?
glucose
- forms a ring structures in solutions
what is the ring that is formed in glucose called?
pyranose ring
what are the two structures of glucose?
alpha-glucose (OH on the opposite side)
beta-glucose (OH on the same side)
differ in orientation of the OH group at C1
where do you find glucose in biology?
- end products of photosynthesis
- energy source in organisms
- cellular respiration
how is the glucose in our blood regulated?
by insulin and glucagon hormones produced by the pancreas
which hormone is produced by the pancreas to prevent sugar levels rising?
insulin
stimulates glycogen formation by binding onto receptors on fats
which hormone is produced by the pancreas to prevent sugar levels from decreasing?
glucagon
stimulates glycogen breakdown
where do the hormones insulin and glucagon go after produced by the pancreas?
liver
how does insulin decrease blood glucose?
- stimulating uptake of glucose in muscle
- prevents breakdown of glycogen to glucose in the liver
- stimulates adipose cells to store glucose as fats
adipose cells store energy
how does glucagon increase blood glucose?
- stimulates the conversion of glycogen to glucose in liver
- breaksdown proteins into amino acids in *muscle cells *
- breaksdown fats on adipose tissues and releases fatty acids
what is the best known endocrine disorder?
diabetes mellitus
what causes diabetes mellitus?
caused by the deficiency of insulin (type 1), or a decreased response to insulin in target tissues (type 2)
where is glucose most commonly found?
disaccharides or starch
what type of monosaccharide is most commonly found in food?
fructose
primary sugar in fruits, vegetables, honey
how is a disaccharide formed?
when a dehydration reactions joins two monosaccharides
what is the covalent bond of disaccharides forming?
glycosidic linkage
what mediates the digestion of disaccharides and other carbohydrates?
mediated by enzymes synthesized by cells lining the small intestine
what is lactose intolerance
*lactose is a disaccharide
result of a drop in lactase production often following childhood
describe the process of lactose intolerance
lactose is usually absorbed in the small intestine, any undigested disaccharide is passed through the large intestine. Lactose intolerance creates an osmotic pull drawing water from surrounding tissue into the intestine causing diarrhea. Bacteria starts to digest the disaccharides which creates gas, bloating and cramps.
what are oligosaccharides?
small sugar polymers that consist of 2-6 monosaccharide units.
where are oligosaccharides most found?
most found attached to glycoproteins and glycolipids ( glycoconjugates )
found in beans and legumes, the human body can not break it down.
glyco=carbohydrate
Name roles of carbohydrates
- involved in cell-to-cell adherence, identification and protection,
what is the major component of mucus?
glycoproteins secreated by goblet cells that protect the respiratory and digestive tracts.
what links together polysaccharides?
dehydration synthesis
how do polysaccharides vary in their properties?
- different isomers
- units are arranged differently
what are the main three polysaccharides that make up of glucose?
1) glycogen
2) cellulose
3) amidon(starch)
name each polysaccharide
1) glycogen
2) cellulose
3) amidon
what are the two types of polysaccharides?
(their functions)
1) energy storage ( starch, glycogen )
2) structural polysaccharides ( cellulose , chitin)
which type of linkage cannot be digested by eukaryotes?
beta-linkages
alpha-linkages can be metabolized and used as an energy source by higher organisms
between starch and glycogen, which has higher branching?
glycogen
branching helps in its solubility
what is the primary storage polysaccharide of animals?
glycogen
ideal for powering short-term metabolism
what is the main storage molecule for plants?
starch
found in high concentrations in tubers ( enlarged root or stem for storage ) and seeds
what is the enzyme amylase?
an enzyme used to breakdown starch into maltose
contained in saliva
pancreas also secretes an enzyme called pancreatic amylase
what type of glucose linkage is cellulose made of?
unbranched chain of beta-glucose
b-glucose allows hydrogen bonds between cellulose molecules
promoting cellulose fibers
name this bond
b-1-4 linkage ( covalent )
name this bond
hydrogen bond
hydrogen bond should be sitting between the two oxygen atoms
what is dietary fiber ?
carbs that humans need for digestion
a group that cellulose is part of
what type of polysaccharide is chitin?
an unbranched polysaccharide
protection of exoskeleton, found in cell walls of yeast and fungi, used to make surgical thread that decomposes as the incision heals
what is peptidoglycan?
bacteria found in cell walls
identifies gram-positive and gram-negative bacteria
what is penicillin?
interferes with peptidoglycan synthesis by inactivating transpeptidases + kills gram positive bacteria
Name this monosaccharide
Glucose
Name this monosaccharide
fructose
Name this monosaccharide
galactose
maltose, lactose, sucrose
