Macromolecules - Biological Systems Lecture 1.3

These flashcards cover key vocabulary terms and concepts related to biological macromolecules as discussed in the lecture.

Polymer

A substance that has a molecular structure built up from a large number of similar units bonded together.

Carbohydrates

Large biological molecules that are a source of energy and provide structural support.

Nucleic Acids

Molecules that store genetic information and function in gene expression.

Proteins

Polymers made of amino acids that have a wide range of functions including catalyzing reactions and transporting substances.

Lipids

A diverse group of molecules that are not true polymers and are hydrophobic; include fats, phospholipids, and steroids.

Dehydration reaction

A process that synthesizes a polymer by removing a water molecule while forming a new bond.

Hydrolysis

A process that breaks down a polymer by adding a water molecule to break a bond.

Monosaccharides

The simplest form of carbohydrates, typically with the molecular formula that is a multiple of CH2O.

Nucleotide

The building block of nucleic acids, composed of a phosphate group, sugar, and nitrogenous base.

Fats

A glycerol molecule joined to three fatty acids

Phospholipids

A glycerol molecule joined to two fatty acids, third hydroxyl is joined to a phosphate group

Steroids

Carbon skeleton consists of four fused rings

_________________ usually have molecular formulas that are some multiple of the unit CH2O

Monosaccharides

Types of polysaccharides

Storage polysaccharides, Structural polysaccharides

Is lipid a true polymer

No

Lipids consists mostly of….

Hydrocarbon regions with relatively non-polar C-H bonds

Lipids like water

False

Type of lipids

Fats, phospholipids, and steroids

What is the difference between phospholipids and fats?

Fats store energy, phospholipids form membranes

DNA full name

Deoxyribonucleic acid

DNA

Encodes all information needed to create life’s diversity

RNA full name

Ribonucleic acid

RNA

Has several roles, but most basic is to deliver information from DNA to sites of protein synthesis

Name the structure

Nucleotide structure

Bases for DNA

Cytosine, Adenine, Thymine, Guanine

Bases for RNA

Cytosine, Adenine, Uracil, Guanine

Parts of the nucleotide structure (middle to outside)

Phosphate group, sugar (pentose), nitrogenous base

Base pairs (DNA)

Adenine paired with Thymine

Cytosine paired with Guanine.

Outside of DNA

Phosphate-sugar backbone

Inside of DNA

Nitrogenous bases

Base pairs (RNA)

Uracil paired with Adenine
Cytosine paired with Guanine.

If we have 30% adenine in a strand of DNA, what is the % of guanine?

30%

DNA strand direction

5’ to 3’

If the DNA strand is 5’ to 3’, what is the complementary stand

3’ to 5’

Antiparallel

Two complementary strands run in opposite directions

What is the matching strand

3’ A A T G 5’

The genetic code

DNA carries hereditary information

Linear order of bases in a gene

Amino acid sequence of a protein, protein structure, protein function

Sequence of bases along DNA (and RNA) are the same for each gene

False

Sequence of bases along DNA (and RNA) is unique for each gene

Steps of DNA replication

• Double helix unravels

• Free bases bond complementary bases on original template strands

• Polymerisation connects the bases together forming two new daughter strands

RNA exists as a ___________

single strand

RNA occurs

Between two RNA molecules or between two stretches of same RNA molecule

Role of DNA

Serves as a template for RNA synthesis

Role of RNA

Copies the message of DNA and transports it to site of protein production: mRNA

mRNA

Linear, and carries message from DNA to protein assembly site

Protein assembly site

Ribosome, a complex protein made up of r(RNA) and proteins, accepts and the mRNA and produces the protein, with the help of tRNA

tRNA

Translate gene language into amino acid sequence

Ribozymes

RNA capable of performing biological function

Peptide bond

A bond between two amino acids

Polypeptide

A chain of amino acids

Protein

Made up one or more polypeptides

Name the structure

Typical AA structure

The AA alphabet

Specific properties of AA affect protein tertiary structure

Four levels of protein structure

1. Primary structure

2. Secondary structure

3. Tertiary structure

4. Quaternary structure

Primary structure

Linear polypeptide chain

Secondary structure

Alpha-helix and beta-pleated sheets (due to hydrogen bonds)

Tertiary structure

Main 3D shape, formed by interactions between side chains

Quaternary structure

Interaction between protein sub units

Examples of the linear sequence of AA

Transthyretin, a transport protein

Segments of the polypeptide chain form coiled or folded patterns due to _________ within the peptide backbone

Hydrogen bonding

Hydrophobic interactions

Away from water and towards each other

Protein denaturation

Structure depends on environmental conditions (pH, salt concentration, temperature)

Protein denaturation (extreme conditions)

Weak chemical bonds can break leading to unravelling of protein

Loss of structure (Protein denaturation)

Loss of function