Bio Lecture 4,5,6 (Macro molecules)

 What are the four classes of macromolecules?

Carbohydrates, Proteins, Nucleic Acids, Lipids.

What is a polymer?

A long molecule consisting of many similar or identical building blocks (monomers) linked by covalent bonds. Ex. Carbohydrates, Proteins, Nucleic Acids

What is a monomer?

Repeating units that serve as building blocks

• Ex. Monosaccharides, Amino Acids, Nucleotides

Define a dehydration reaction

• A chemical reaction in which two monomers are covalently bonded to each other with the loss of a water molecule. Monomer → Polymer

Define hydrolysis

A reaction that breaks bonds between monomers by adding water. Polymer → Monomer

What are carbohydrates?

Sugars and polymers of sugars, which serve as fuel and building material

What are monosaccharides?

The simplest carbohydrates, or single sugars (e.g., glucose most common monosaccharide). Monomer: monosaccharides

What are disaccharides?

Two monosaccharides joined by a glycosidic linkage (e.g., sucrose). They are bonded by Covalent bond: glycosidic linkage

What are polysaccharides?

Polymers of sugars that have storage and structural roles, Multiple Monosaccharides=  Polymer: polysaccharides(e.g., starch, cellulose)

What are the two types of polysaccharides?

Storage polysaccharides (e.g., starch[plants], glycogen[animals]) and structural polysaccharides (e.g., cellulose(tough wall in plant cells), chitin (exoskeleton of arthropods and cell walls of many fungi)).

What is a lipid?

• A class of hydrophobic molecules that are not polymers nor monomers, including fats, phospholipids, and steroids. Bonded by Covalent Bond: Ester Linkages

What is a fat (triacylglycerol)?

• A molecule consisting of glycerol(Vertical Part) and three fatty acids(Long “tails”), used for energy storage.

What is the difference between saturated and unsaturated fats?

• Saturated fats have no double bonds between carbon atoms (solid at room temp); unsaturated fats have one or more double bonds (liquid at room temp).

Trans Fats

Make “kink” Unsaturated Fat into Saturated Fat

78. What is a phospholipid?

•  A molecule that makes up the bilayer of cell membranes, with a hydrophilic head and two hydrophobic tails(one is “kinked”).

What are steroids?

Lipids characterized by a carbon skeleton consisting of four fused rings (e.g., cholesterol Component in animal cell membranes).

What are proteins?

Macromolecules made of amino acids that perform a vast array of functions in living organisms. Monomer: Amino Acids . Polymer: Polypeptides . bonded by Covalent bond: Peptide Bonds’

What are the 8 types of proteins

Enzymatic Proteins, Defensive Proteins, Storage Proteins, Transport Proteins, Hormonal Proteins, Receptor Proteins, Contractile and motor proteins, Structural Proteins

Enzymatic Proteins

Selective acceleration of chemical reactions. Speeds up reaction by lowering activation energy, ends in “ase”. Examples: Lipase- Lipids     Lactase-Lactase 

Defensive Proteins

Protection against disease. Examples: Antibodies-inactivates bacteria & viruses

Storage Proteins

Storage of Amino Acids For later use, for example,Casein

Transport Proteins

Transport of substances. Moves substances through the body. Example: hemoglobin carries oxygen in red blood cells.

Hormonal Proteins

Coordination of an organism’s activities. Hormones are not always proteins. They are chemical messengers. Hormones don’t do things they signal other things to do things. Example: insulin secreted by pancreas signals.

Receptor Proteins

Response of cell to chemical stimuli. Receivers of chemicals, allows communication between cells. examples: T cell receptors bar to antigens to trigger an immune response.

Structural Proteins

Provides support, shape, and strength to cells. Example: collagen keratin.

Contractile and motor proteins

Movement. responsible for undulations of Cilia and flagella. example: myosin and act and found in muscle cells.

What is the structure of an amino acid?

Amino acids have a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable side chain (R group).

What are the four levels of protein structure?

• Primary (sequence of amino acids), Secondary (Coil and folds result from hydrogen bonding

• Alpha-helix and Beta-pleated sheets), Tertiary (3D shapeIt gives it the overall shape of the polypeptide

• Results of from the R (side chain) group

• Include a lot of different bonds and interactions

• NOTE: strong covalent bonds called disulfied bridges reinforce the protein’s structure),

• Quaternary (association of multiple polypeptidesTwo ore more polypeptide chains form one whole macromolecule

• NOT ALL PROTIENS HAVE QUATERNARY STRUCTURE

What are nucleic acids?

Polymers made of nucleotide monomers, including DNA and RNA, that store and transmit hereditary information bonded by Covalent bond: Phosphodiester Bond.

What is the difference between DNA and RNA?

 DNA contains deoxyribose and the bases A, T, C, G; RNA contains ribose and the bases A, U, C, G.

What are the three components of a nucleotide?

A nitrogenous base, a pentose sugar, and one or more phosphate groups

What is a nucleoside

A nucleoside is a molecule consisting of a nitrogenous base attached to a sugar (ribose or deoxyribose) without a phosphate group.

What are the components of a nucleoside?

A nucleoside is made up of two components:

1. A nitrogenous base

2. A sugar (ribose in RNA, deoxyribose in DNA)

 What are pyrimidines?

Pyrimidines are nitrogenous bases that have a single six-membered ring structure. Examples of pyrimidines include cytosine, thymine (in DNA), and uracil (in RNA).

Name three examples of pyrimidines.

1. Cytosine (C) – Found in both DNA and RNA.

2. Thymine (T) – Found only in DNA.

3. Uracil (U) – Found only in RNA, replacing thymine.

What are purines?

 Purines are nitrogenous bases that have a two-ring structure, consisting of a five-membered ring fused to a six-membered ring. Examples of purines are adenine and guanine.

 Name two examples of purines.

1. Adenine (A) – Found in both DNA and RNA.

Guanine (G) – Found in both DNA and RNA

What is the difference between pyrimidines and purines?

Pyrimidines have a single six-membered ring, while purines have a two-ring structure (a five-membered ring fused to a six-membered ring). Pyrimidines include cytosine, thymine, and uracil, while purines include adenine and guanine.

Which nitrogenous base is only found in RNA?

Uracil (U) is found only in RNA, where it pairs with adenine, replacing thymine, which is found in DNA

 Which nitrogenous base is only found in DNA?

Thymine (T) is found only in DNA and pairs with adenine.