4: Biomolecules

Organic

used to describe compounds that contain carbon, specifically C--C or C--H bonds.

Functional Groups

used to describe certain arrangements of atoms attached to the carbon core of many organic molecules. Also called radicals.

Free Radical

a functional group that is temporarily unattached and is highly reactive because of unpaired electrons.

1:2:1

All carbohydrate compounds contain the elements carbon, hydrogen, and oxygen, usually in the ratio of what?

Simple sugars

They provide the main source of energy for cells.

complex carbohydrates

They may provide temporary energy storage for cells.

Monosaccharides

Simplest form of carbohydrates, consisting of one sugar unit. Glucose, fructose, galactose, ribose, deoxyribose.

Disaccharides

Carbohydrates formed by two monosaccharides linked together. Sucrose (table sugar), lactose (milk sugar), maltose.

Polysaccharides —Complex carbohydrates formed by many monosaccharide units. Glycogen, starch, cellulose.

Glucose

the most important simple sugar; a six-carbon sugar with the formula C 6 H 12 O 6. It is present in the dry state as a straight chain but curls into a cyclic compound (ring) when dissolved in water.

Polymer

any large molecule made up of many identical small molecules.

Glycogen

a polymer of glucose, is sometimes referred to as animal starch; the main polysaccharide in the body and has an estimated molecular weight of several million..

Lipids

these are water-insoluble organic biomolecules, as they are non-polar. They include fats, waxes, oils, hormones, and certain components of membranes and function as energy-storage molecules and chemical messengers.

Triglycerides

also known as fats, are the most abundant lipids, and they function as the body’s most concentrated source of energy.

Glycerol

forms the backbone of triglycerides by bonding with three fatty acids.

Fatty Acids

the building blocks of the fat in our bodies and in the food we eat.

Saturated Fatty Acids

a fatty acid where all carbon atoms are fully saturated with hydrogen; no double bonds. Mainly from animal fats.

Monounsaturated Fatty Acids

a fatty acid where one double bond in the hydrocarbon chain. Plant oils.

Polyunsaturated Fatty Acids

a fatty acid where two or more double bonds in the hydrocarbon chain. Vegetable oils

Glycerol & 3 fatty acids

building blocks of triglycerides.

Glycerol tricaproate

a composite molecule made up of three molecules of caproic acid (a six-carbon fatty acid) coupled in a dehydration synthesis reaction to a single glycerol backbone

Hydrophilic

water loving.

Hydrophobic

water fearing.

Phosphoinositides (PIs)

make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death.

Steroids

a large and important class of lipids whose molecules have as their main feature nucleus. Its nucleus is composed of four attached rings that are structurally similar but may have widely diverse functions related to the differing functional groups that are attached to them.

Cholesterol

a steroid found in the plasma membrane surrounding every body cell. It is also used to make the bile salts needed for digestion. It can travel in the blood only after it has attached to a protein molecule—forming a lipoprotein.

Lipoprotein

these are particles made of protein and fats. They carry cholesterol through bloodstream to the cells.

High-Density Lipoprotein

also known as good cholesterol, it help removes other forms of cholesterol in the bloodstream.

Low-Density Lipoprotein

also known as bad cholesterol, this carries cholesterol to the blood, and helps buildup of cholesterol in arteries.

Prostaglandins (PGs)

also known as tissue hormones, are lipids composed of a 20-carbon unsaturated fatty acids that contains a five carbon ring.

cyclooxygenase (COX)

If a specific type of enzyme, __is present to interact with these fatty acids, prostaglandins will be synthesized and released from the cell membrane into the surrounding tissue fluid.

Aspirin

a commonly used cyclooxygenase (COX) inhibitor that reduces prostaglandin effects in the body such as inflammation, fever, and blood clotting.

Protein

the most abundant of the organic compounds in the body.

Structural Proteins

Provide support, strength, and structure to cells and tissues. Maintains cell shape, integrity, contribute to the structure of tissues and organs.

Functional Proteins

Performs specific biological activities, such as catalysing reactions, transporting molecules, or defending the body.

Amino Acids

formed when the elements that make up a protein molecule are bonded together.

Peptide Bond

one that binds the carboxyl group of one amino acid to the amino group of another amino acid.

Peptide

a compound formed when O from the negative carboxyl group of one amino acid and two H atoms from the positive amino group of another amino acid split off to form water.

Dipeptide

a peptide made up of only two amino acids linked by a peptide bond.

Tripeptide

this consists of three amino acids linked by two bonds.

Polypeptide

a long sequence or chain of amino acids—usually 100 or more—linked by peptide bonds.

Primary Structure

protein structure where the sequence of amino acids in a polypeptide chain.

Secondary Structure

protein structure where local folding of the polypeptide chain into alpha helices or beta-pleated sheets

Tertiary Structure

protein structure where the overall 3D shape of a single polypeptide chain, formed by further folding of the secondary structure.

Quaternary Structure

protein structure where the arrangement of two or more polypeptide chains into a larger, multi-subunit protein complex.

Parathyroid hormone (PTH)

a protein that retains its primary structure—it is a noodle-like molecule consisting of only one polypeptide chain of 84 amino acids..

Motif

a commonly occurring pattern of alpha helices and/or beta sheets within the secondary structure.

Domains

a tertiary structure may include several complicated “knots”.

Keratin

a threadlike fibrous protein that is rich in the sulphur-containing amino acid cysteine.

Disulphide Linkages

bonds formed when the protein chains in keratin are linked in numerous places by S—S bonds that form between cysteines within each hair shaft.

Chaperones

a group of proteins that acts to direct the steps required for many proteins to fold into the twisted and convoluted shape required for them to function properly.

Chaperonins

oligomeric proteins that assist in the folding of nascent or denatured proteins.

Ribbon Model

model that shows the areas where alpha helices and folded sheets form within the molecule.

Space-filling Model

model that shows each atom as a “cloud” filling up the space occupied by that atom.

Surface-rendering model

model that shows the three-dimensional boundaries of the whole protein molecule and often colour-coding for charged regions on the surface of the protein.

Native State

the final, functioning shape for a protein.

Denatured Protein

occurs when a protein loses its normal folded organization and thus loses its functional shape.

Renatured Protein

occurs when the protein shape is restored, resuming its normal function.

Receptors

Binding sites of certain proteins on surfaces of cell membranes serve as __ for insulin and various other hormones.

Nucleic Acid

polymers of nucleotides.

Nucleotides

the basic building block of nucleic acids.

Deoxyribonucleotide

consists of the pentose sugar, deoxyribose, a nitrogenous base (either adenine, cytosine, guanine, or thymine), and a phosphate group.

Ribonucleotides

contains the sugar ribose instead of deoxyribose and the nitrogenous base uracil instead of thymine.

DNA

Double-stranded; forms a double helix. Primarily in the cell nucleus. Stores genetic information and passes it from generation to generation.

RNA

Single-stranded (can fold into complex structures). Acts as a temporary copy of DNA for protein synthesis and regulation.

Adenine (A), Thymine (T), Guanine (G), Cytosine (C)

nucleotides of the DNA.

Adenine (A), Uracil (U), Guanine (G), Cytosine (C)

nucleotides of the RNA.

Purine bases

adenine and guanine; bases that have double ring structure.

Pyrimidine Bases

cytosine and thymine; bases that have a single ring structure. Uracil replaces thymine in RNA.

Messenger RNA (mRNA)

Acts as a temporary copy of a gene from DNA. It carries the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm, where the proteins are synthesized.

Transfer RNA (tRNA)

Responsible for bringing the correct amino acid to the ribosome during protein synthesis. It has an anticodon that matches with the mRNA codon, ensuring the correct sequence of amino acids in a protein.

Ribosomal RNA (rRNA)

Forms the structural and functional components of ribosomes, which are the cellular structures where protein synthesis occurs. It helps catalyze the assembly of amino acids into protein chains

Small Nuclear RNA (snRNA)

Involved in the processing of pre-mRNA, including the removal of introns (non-coding regions) and splicing of exons (coding regions) to form mature mRNA

MicroRNA (miRNA)

Small RNA molecules that regulate gene expression by binding to complementary mRNA sequences, leading to mRNA degradation or inhibition of translation.

Long Non-Coding RNA (lncRNA)

Involved in regulating gene expression at various levels, including chromatin modification, transcription, and post-transcriptional processing. It does not code for proteins but have roles in regulatory processes

Ribozymes

RNA molecules that act as enzymes to catalyze biochemical reactions, such as the cleavage of RNA molecules during RNA processing.

Adenosine Triphosphate (ATP)

a molecule composed of adenosine (adenine and ribose sugar), to which attached a string of three phosphate groups.

High energy bonds

covalent bonds that link the phosphate groups; because when they are broken during catabolic chemical reactions, the energy is released to form new compounds.

Adenosine Diphosphate (ADP)

an inorganic phosphate group, a set of enzyme reactions splitted when they releases the energy that is stored in ATP.

Adenosine Monophosphate (AMP)

an inorganic phosphate group, the splitting of ADP.

Cyclic Adenosine Monophosphate

a one-phosphate molecule that is used as an intracellular signal within cells.

Creatine phosphate (CP)

a high-energy molecule made up of an amino acid derivative and a phosphate connected with a high-energy bond. This is where muscles turn into, when ATP is short in energy supply.

high ATP concentration

A cell at rest has concentration.

low ATP concentration

An active cell has concentration.

high ADP concentration

An exhausted cell has concentration.

Nicotinamide adenine dinucleotide (NAD+) and Flavin adenine dinucleotide (FAD)

act as coenzymes to shuttle energy-carrying particles (electrons) from one metabolic pathway to another during the many complicated steps of transferring energy from food molecules to ATP.

Glycoproteins

Large proteins with small carbohydrate groups attached. Similar to functional proteins.

Proteoglycans

Large polysaccharides with small polypeptide chains attached. Lubrication; increase thickness of fluid.

Lipoproteins

Protein complex containing lipid groups. Transport lipids in the blood.

Glycolipids

Lipid molecule with attached carbohydrate group. Component of cell membranes.

Ribonucleoprotein

Combination of RNA nucleotide and protein. Enzyme-like actions such as splicing mRNA.

Diabetes Mellitus (DM)

A chronic disorder where the body cannot efficiently use glucose for energy due to impaired glucose transport into cells.

Hyperlipidaemia

High blood concentrations of cholesterol or triglycerides, often linked to heart disease and stroke.