Chapter 5- Biochemistry (2) Flashcards
Where are glycoproteins and glycolipids found?
On cell surfaces for cell recognition.
What is a monosaccharide?
Monosaccharides- composed of one simple sugar like glucose and fructose
What is the general formula of a monosaccharide?
CH20
Within the structure of a monosaccharide, there is always a double bond to what?
Oxygen
What is an aldehyde?
When the double bond to oxygen is found on the carbon at the end of the chain.
What is a ketone?
If the double bond to oxygen is found on the carbon at the middle of the chain.
In aqueous solution, the aldehyde or ketone group of a sugar molecule tends to react with what and what does this cause?
Reacts with a hydroxyl group of the same molecule, thereby closing the molecule into a ring.
What is a disaccharide?
When two monosaccharides join together via a condensation reaction.
What is the bond formed between a disaccharide?
A glycosidic bond
What type of bond is a glycosidic bond?
A covalent bond
What are the common disaccharides?
1- Sucrose- glucose + fructose
2- Lactose- galactose + glucose
3- Maltose- glucose + glucose
What are oligosaccharides?
Polymers containing a small number of monosaccharides.
What do oligosaccharides play a role in?
Cell- cell recognition- glycocalyx
What do oligosaccharides help form?
Glycoproteins and glycolipids
What is the glycocalyx made up of?
Glycoproteins
Proteoglycans and glycoproteins are composed of what?
Protein and carbohydrate
Proteoglycans play an important role in what?
Connective tissues. They form the ground substance of connective tissues
What are some of the functions of proteoglycans?
1- Create hydrated spaces around cells and withstand compression.
2- Can regulate fluid and can bind cations (e.g, zinc, iron, copper).
What is the proteoglycan structure?
Sticking out from the proteoglycan protein chain are glycosaminoglycans (GAGS) which are chains of repeating disaccharide units.
GAGS extend out from the core protein to form what sort of structure?
Proteoglycan- bottle brush structure
What are some examples of proteoglycans?
1- Hyaluronic acid
2- Keratan sulphate
What is a polysaccharide?
Is a polymeric carbohydrate molecule composed of long chains of monosaccharide units.
What are polysaccharides used for?
Storage or structural purposes
