What is the general formula for carbohydrates?
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(C.H2O)n.
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What is the general formula for carbohydrates?
(C.H2O)n.
What is the role of glycolipids in the plasma membrane?
They act as specific sites for cell recognition on the plasma membrane.
What are glycolipids composed of?
Carbohydrate and lipid.
What is an aldehyde group?
A functional group characterized by a carbon atom bonded to a hydrogen atom and a double bond to an oxygen atom (–CHO).
What are polysaccharides?
Polymeric carbohydrates that contain many monosaccharide units bonded together by glycosidic bonds.
What are monosaccharides?
Simple sugar molecules that are the basic building blocks of carbohydrates.
How are monosaccharides categorized?
By the number of carbon atoms (3-8) and whether they are aldehyde or ketone.
What are disaccharides made of?
A pair of monosaccharides.
Where are proteoglycans primarily found?
In the extracellular matrix (ECM).
What characterizes non-reducing disaccharides? Example?
They have no hemiacetal group on C1 (e.g., Sucrose).
How does glycosylation affect the subunits of TSH, FSH, and LH?
It increases their stability in circulation and enhances their affinity and specificity for receptors.
What is the storage form of glucose in animals?
Glycogen.
What role do proteoglycans play in skin?
They help restore cells, hydrate the ECM, and prevent wrinkles.
What is the definition of metabolism?
Metabolism is the sum of catabolism and anabolism.
What are glycolipids?
Lipid glycoconjugates formed in the Golgi apparatus.
How are disaccharides formed?
Through dehydration synthesis/condensation process.
What is a glycoprotein made of?
Oligosaccharide and protein.
What is common among TSH, FSH, and LH?
They all share the same α-glycoprotein subunit (α-GSU).
What are Glycosaminoglycans (GAGs) also known as?
Mucopolysaccharides.
What are the two types of starch?
Amylose and amylopectin.
What is a ketone group?
A functional group characterized by a carbon atom double-bonded to an oxygen atom and bonded to two other carbon atoms (–C(=O)–).
How are polysaccharides classified?
Based on identity of repeating monosaccharide units, length of chains, types of bonds linking the units, and degree of branching.
What does a Type A person have that affects their blood type?
Transferase that attaches GalNac to H Substance.
How are glycoproteins transported to the plasma membrane?
Via vesicles.
Why can't humans digest corn husk or wood?
Humans do not have the cellulase enzyme.
What is the definition of carbohydrates?
Hydrates of Carbon.
What is a proteoglycan composed of?
Glycosaminoglycan (GAG) and protein.
What type of bond links monosaccharides in disaccharides?
Glycosidic bond (glycosidic linkage).
What are the three pituitary N-linked glycoprotein hormones?
Thyroid-stimulating hormone (TSH), Follicle-stimulating hormone (FSH), and Luteinizing hormone (LH).
What is the major carbohydrate found in milk?
Lactose.
Where are glycoproteins primarily found?
In the cell membrane, extending outwards into the extracellular matrix (ECM).
How are carbohydrate chains added to glycoproteins?
In the lumen of the endoplasmic reticulum (ER) and the Golgi complex.
What is another name for polysaccharides?
Glycans.
What are glycosphingolipids and where are they abundant?
They are a type of glycolipid abundant in neurons, aiding in nerve conduction and myelin formation.
Give examples of glycoproteins.
Antibodies, human blood group antigens, and hormones like FSH, LH, and TSH.
What is the charge of Glycosaminoglycans?
Negatively charged.
What are proteoglycans?
Proteins that are heavily glycosylated.
Where does protein synthesis for glycoproteins take place?
In the rough endoplasmic reticulum (RER).
What is O-linked glycosylation?
When carbohydrates link to the oxygen atom of the side chain of serine or threonine amino acid residues.
What are the two main types of polysaccharides based on repeating monosaccharide units?
Homo polysaccharides and hetero polysaccharides.
What are ABO blood group antigens?
Complex carbohydrates present in glycoproteins and glycolipids of RBC membrane.
What does a Type B person have that affects their blood type?
Transferase that attaches Gal to H Substance.
What process splits disaccharides into monosaccharides?
Hydrolysis with the help of enzymes (sucrase, lactase, maltase).
What distinguishes the β subunit in TSH, FSH, and LH?
The β subunit is specific to each hormone (β-TSH, β-FSH, and β-LH are unique).
What is the lactose content in breast milk compared to cow milk?
Breast milk contains 7% lactose, while cow milk contains 5%.
What is the storage form of glucose in plants?
Starch.
What key role do Glycosaminoglycans play?
Cell signaling.
What is glycosylation?
A process where carbohydrate molecules are attached to protein molecules, resulting in a glycoprotein.
What functional groups do carbohydrates contain?
Hydroxyl groups (-OH).
What are glycoconjugates?
Carbohydrates covalently linked with other biomolecules.
What do Type AB individuals possess?
Both transferases.
What are TSH, FSH, and LH composed of?
They are heterodimers composed of an α subunit (α-glycoprotein subunit) and a β subunit.
What is N-linked glycosylation?
When carbohydrates are attached to the nitrogen of the side chain of the amino acid asparagine.
What does a Type O person lack?
Neither transferase.
Where are glycolipids commonly found?
In brain nerve tissues and cell membranes.
What is the basic unit of a proteoglycan?
A core protein with one or more covalently linked GAG chains.
Which hormone stimulates the synthesis of lactose?
Prolactin.
What polysaccharide provides support to plant cell walls?
Cellulose.
What polysaccharide provides support in insects and fungi?
Chitin.
What is the reaction of non-reducing disaccharides to Benedict's reagent?
They do not react.
From what substance can lactose be entirely synthesized?
Glucose.
How do proteoglycans function in cartilage?
They retain water, allowing cartilage to act as a shock absorber and maintain strength.
What role do glycolipids and glycoproteins play in cells?
They send messages or signals between and within the cells.
Give an example of O-linked glycoproteins.
ABO blood group.
Where is lactose synthesized in humans?
In the mammary gland of an adult female during lactation.
What are glycoproteins?
Short carbohydrate chains covalently attached to Serine/Threonine or asparagine residues in proteins.
What types of uronic acids can be found in GAGs?
Glucuronate or iduronate.
What is a consequence of sphingolipidoses in the nervous system?
Prevents ganglioside degradation, leading to nervous dysfunction.
What are examples of proteoglycans found in cartilage?
Aggrecan.
Give examples of N-linked glycoproteins.
FSH, LH, TSH, and Erythropoietin.
What are sphingolipidoses?
Human metabolic storage disorders characterized by the accumulation of harmful quantities of glycosphingolipids and phosphosphingolipids due to enzyme disruption in sphingolipid metabolism.
4 functions of Carbohydrates.
Source of energy
Important in cell structure and function.
Molecule modification
Importnat in Self-Recognition of cells.
What characterizes reducing disaccharides? Example?
They have a hemiacetal group on C1 (e.g., Lactose and Maltose).
What are the steps to make lactose?
Glucose-1-phosphate + UTP —> UDP-glucose (activated form)
UDP-Glucose —> UDP Galactose via Epimerase
UDP-Galactose + Glucose —> Lactose via Lactose synthase (galactosyltransferase)
alpha-lactalbumin also needed in last step to lower Km for glucose
What is the structure of Glycosaminoglycans?
Long unbranched polysaccharides containing repeating disaccharide units. Disaccharide units contain either GalNAc or GlcNAc.
What is a characteristic of amylopectin?
Has 1-4 and 1-6 bonds and consists glucose like starch. It is insoluble and acts as an energy supplement for plants.
What is a characteristic of amylose?
Has 1-4 bonds and is composed of glucose. It dissolves in hot water and stores energy.
