Biochem Carbs&Pro

Questions and Answers

Which amino acid is classified as nutritionally semi-essential?

Arginine (correct)

Histidine

Phenylalanine

Leucine

What is the primary factor that stabilizes the tertiary structure of a protein?

Covalent bonds

Hydrophobic interactions (correct)

Carbohydrate interactions

Peptide bonds

Which of the following amino acids cannot be synthesized in the body and must be obtained through diet?

Tryptophan (correct)

Tyrosine

Cystine

Arginine

What does the acronym 'PVT TIM HALL' help to remember?

The essential amino acids Signup and view all the answers

Which statement best defines the quaternary structure of a protein?

The interaction of multiple polypeptide chains and their assembly Signup and view all the answers

What are the characteristics of monosaccharides?

They are simple sugars. Signup and view all the answers

Which of the following statements about isomers is true?

Isomers can be classified as ketoses or aldoses. Signup and view all the answers

How is the configuration of D- and L- sugars determined?

Based on spatial orientation of glycerose. Signup and view all the answers

Which type of polysaccharide has both α-1,4 and α-1,6 glycosidic bonds?

Glycogen Signup and view all the answers

What is the primary dietary role of cellulose?

Adds bulk to the diet as fiber. Signup and view all the answers

Which statement correctly describes polysaccharides?

They are formed by the condensation of more than 10 monosaccharide units. Signup and view all the answers

Which of the following is NOT a type of polysaccharide?

Glucose Signup and view all the answers

What is a characteristic of inulin in the body?

It is not hydrolyzed in the body. Signup and view all the answers

What is the main structural feature that distinguishes amylose from amylopectin?

Amylose is a linear chain of glucose linked by α-1,4 bonds, whereas amylopectin is branched. Signup and view all the answers

Which type of polysaccharide contains only one type of sugar unit?

Homopolysaccharides Signup and view all the answers

In which structure does the anomeric carbon's hydroxyl group position depend on the form being alpha or beta?

Anomers Signup and view all the answers

Which of the following statements about glycogen is true?

Glycogen is more branched than amylopectin. Signup and view all the answers

What characterizes heteropolysaccharides?

Contain more than one type of sugar unit. Signup and view all the answers

Which term describes molecules that are mirror images of each other?

Enantiomers Signup and view all the answers

What is the expected structure of monosaccharides with five or more carbon atoms in aqueous solutions?

Cyclic structures Signup and view all the answers

What type of bond is primarily found in the structure of amylose?

α-1,4 bonds Signup and view all the answers

How are epimers defined in carbohydrate chemistry?

Isomers that differ in the configuration around one specific carbon. Signup and view all the answers

Which of the following is an example of a heteropolysaccharide?

Chondroitin sulfate Signup and view all the answers

Which function of proteins is primarily associated with hemoglobin?

Transport and storage Signup and view all the answers

What is the simplest amino acid, which also plays a role in the first step of heme synthesis?

Glycine Signup and view all the answers

What type of protein is primarily involved in the transmission of nerve impulses?

Neurotransmitters Signup and view all the answers

Which amino acid is involved in the transamination of pyruvate?

Alanine Signup and view all the answers

What major role do glycoproteins serve in cellular structures?

Cell signaling Signup and view all the answers

Which proteins provide mechanical support in connective tissues?

Collagen and keratin Signup and view all the answers

What is the primary function of gamma globulins?

Provide immune protection Signup and view all the answers

In the context of protein functions, which statement about enzymes is correct?

They act as catalysts in chemical reactions. Signup and view all the answers

What defines the proteome of a cell?

The set of all proteins expressed by a cell at a given time Signup and view all the answers

Which of the following functions is NOT typically associated with proteins?

Storing genetic information Signup and view all the answers

What is the primary focus of proteomics?

Identification of all proteins produced by a cell Signup and view all the answers

Which of the following amino acids is not classified as nutritionally essential?

Tyrosine Signup and view all the answers

What condition is associated with the accumulation of branched-chain amino acids?

Maple syrup urine disease Signup and view all the answers

Which amino acid has the largest side chain and is a precursor for serotonin?

Tryptophan Signup and view all the answers

What is the term for amino acids that must be present in the human diet?

Nutritionally essential amino acids Signup and view all the answers

Which amino acid is linked to N-linked glycosylation of proteins?

Asparagine Signup and view all the answers

Which amino acid is converted to ammonia by glutaminase?

Glutamine Signup and view all the answers

What are the primary products of amino acid interconversion by tissue aminotransferases?

α-ketoglutarate and oxaloacetate Signup and view all the answers

Which amino acid is crucial for the development of phenylketonuria?

Phenylalanine Signup and view all the answers

What distinguishes essential amino acids from non-essential amino acids?

Essential amino acids must be obtained from the diet. Signup and view all the answers

Study Notes

Polysaccharides and Monosaccharides

Polysaccharides are carbohydrate polymers composed of over ten monosaccharide units.
Monosaccharides are the simplest form of carbohydrates and cannot be hydrolyzed further.
Sugar units are connected via glycosidic bonds.
Monosaccharides are classified as ketoses or aldoses and based on the number of carbon atoms present.
Examples include glucose (aldehyde) and galactose (different –OH at C4) as well as glucose and mannose (different –OH at C2).

Isomerism in Monosaccharides

D- and L- isomerism pertains to the spatial orientation of monosaccharides.
Enantiomers are mirror images of each other, distinguished as D-sugars (dextrorotatory) and L-sugars (levorotatory).
Anomers differ at the anomeric carbon, with alpha (α) having the -OH below the ring and beta (β) above.

Types of Polysaccharides

Homopolysaccharides (homoglycans) contain one type of sugar unit, e.g. starch, glycogen, cellulose, and inulin.
Heteropolysaccharides (heteroglycans) consist of multiple types of sugar units, e.g. heparin, hyaluronic acid, and chondroitin sulfate.
Amylose is about 20% of starch; it has a linear structure linked by α-1,4 bonds.
Amylopectin (>80% of starch) consists of branched chains with both α-1,4 and α-1,6 bonds.
Glycogen exhibits even greater branching with α-1,4 and α-1,6 bonds occurring every 8 to 12 residues.

Amino Acids and Proteins

Proteins are linear polymers of amino acids with diverse functions, such as enzyme catalysis, transport, mechanical support, and immune protection.
Only 20 amino acids are commonly found in mammalian proteins; 8 are essential (cannot be synthesized) and termed “nutritionally essential.”
Non-essential amino acids are synthesized in the body but are still metabolically crucial.

Structure of Amino Acids and Proteins

Amino acids consist of a central carbon, amino group, carboxylic acid group, hydrogen atom, and side chain (R group).
Essential amino acids include phenylalanine, valine, leucine, isoleucine, threonine, methionine, histidine, tryptophan, and lysine.
Arginine is semi-essential, synthesized from dietary sources but also produced in the body.
Tertiary structure is the overall 3D shape of proteins, stabilized by various bonds (disulfide, hydrophobic interactions, hydrogen bonds, ionic bonds).
Quaternary structure refers to the assembly of multiple polypeptide chains into functional units.

Additional Concepts

Glycine is the simplest amino acid and plays a role in heme synthesis and neurotransmission.
Alanine acts as a carrier of ammonia and carbon from muscle to liver and is involved in transamination reactions.
Branched-chain amino acids (valine, leucine, isoleucine) are essential and interconvertible via tissue aminotransferases.
Phenylalanine is a precursor to tyrosine and accumulates in phenylketonuria.

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Description

This quiz covers the basics of polysaccharides and monosaccharides, including their structure, classification, and isomerism. Participants will explore the significance of glycosidic bonds and different types of carbohydrate units. Test your knowledge on key concepts and examples such as glucose, galactose, and various polysaccharides.