Biomolecules Class 11 Biology Flashcards

This set of vocabulary flashcards covers the fundamental concepts of biomolecules, including chemical analysis methods, the structure and function of amino acids, lipids, proteins, polysaccharides, nucleic acids, and the kinetics and classification of enzymes based on the Chapter 9 transcript.

Biomolecules

All the carbon compounds that are obtained from living tissues.

Acid-soluble pool

The filtrate obtained during chemical analysis of living tissue in $Cl_3CCOOH$, containing thousands of organic compounds with molecular weights ranging from $18$ to around $800$ daltons.

Acid-insoluble fraction

Also called the retentate, this fraction contains proteins, nucleic acids, polysaccharides, and lipids.

Dry weight

The weight of living tissue after all the water has been evaporated.

Ash

The remaining material after living tissue is fully burnt and all carbon compounds are oxidised to gaseous form ($CO_2$, water vapour), containing inorganic elements like calcium and magnesium.

$\alpha$-amino acids

Organic compounds containing an amino group and an acidic group as substituents on the same carbon, which is the $\alpha$-carbon; they are considered substituted methanes.

Zwitterionic form

The state of an amino acid in solution where both the $-NH_2$ and $-COOH$ groups are ionized, and the structure changes depending on the pH of the solution.

Palmitic acid

A saturated fatty acid which has $16$ carbons, including the carboxyl carbon.

Arachidonic acid

An unsaturated fatty acid which has $20$ carbon atoms, including the carboxyl carbon.

Glycerol

A simple lipid also known as trihydroxy propane.

Phospholipids

Lipids that contain phosphorus and a phosphorylated organic compound, found in cell membranes; Lecithin is a specific example.

Nucleosides

Compounds formed when a nitrogen base is attached to a sugar, such as adenosine, guanosine, thymidine, uridine, and cytidine.

Nucleotides

Compounds serving as the building blocks of nucleic acids, consisting of a nitrogen base, a sugar, and a phosphate group esterified to the sugar.

Primary metabolites

Biomolecules that have identifiable functions and play known roles in normal physiological processes in living organisms.

Secondary metabolites

Compounds like alkaloids, flavonoids, rubber, antibiotics, and coloured pigments produced by plants, fungi, and microbes whose specific physiological roles are not always understood.

Biomacromolecules

Chemical compounds found in the acid insoluble fraction with molecular weights in the range of ten thousand daltons and above, excluding lipids.

Proteins

Heteropolymers consisting of linear chains of amino acids linked by peptide bonds.

Collagen

The most abundant protein in the animal world.

RuBisCO

Ribulose bisphosphate Carboxylase-Oxygenase; the most abundant protein in the whole of the biosphere.

Essential amino acids

Amino acids that cannot be made by the body and must be supplied through the diet.

Cellulose

A homopolymeric polysaccharide consisting of only one type of monosaccharide, which is glucose, and a primary component of plant cell walls.

Inulin

A polymer of fructose.

Chitin

A complex polysaccharide used in the exoskeletons of arthropods.

Primary structure

The sequence of amino acids in a protein, representing its positional information.

Tertiary structure

The 3-dimensional view of a protein formed when the long protein chain is folded upon itself like a hollow woolen ball; it is necessary for biological activity.

Quaternary structure

The architectural arrangement of individual folded polypeptides or subunits in a protein, such as the four subunits of human haemoglobin.

Ribozymes

Nucleic acids that behave like enzymes.

Active site

A crevice or pocket in an enzyme formed by the folding of the protein chain into which a substrate fits.

Activation energy

The difference between the average energy content of the substrate and the energy of the transition state.

Competitive inhibitor

A chemical that closely resembles a substrate in molecular structure and competes for the enzyme's active site, such as malonate inhibiting succinic dehydrogenase.

Prosthetic groups

Organic co-factors that are tightly bound to the apoenzyme, such as haem in peroxidase and catalase.

Co-enzymes

Organic co-factors whose association with the apoenzyme is transient and often contain vitamins like niacin in NAD and NADP.

Apoenzyme

The protein portion of an enzyme that requires a co-factor to become catalytically active.

Metabolic pathway

A multistep chemical reaction where each step is catalysed by the same or different enzymes, such as the ten-step conversion of glucose to pyruvic acid.

Oxidoreductases

Enzymes that catalyse oxidoreduction between two substrates ($S$ and $S'$).

Lyases

Enzymes that catalyse the removal of groups from substrates by mechanisms other than hydrolysis, leaving double bonds.

Ligases

Enzymes that catalyse the linking together of two compounds, such as joining $C-O$, $C-S$, $C-N$, or $P-O$ bonds.