Anas Zoology

Amino acids are compounds containing carbon, hydrogen, oxygen and nitrogen. They serve as monomers of proteins. Amino acids contains an amino group, a carboxyl group, a hydrogen atom and a distinctive side chain, all these are bonded to the same carbon atom, this carbon atom is called as ∝-carbon. The amino acids differ with respect to the side chain attached to their ∝-carbon. General structure of Amino Acid This general structure is common to all amino acids except for one i.e. proline. The side chain attached to the ∝-carbon atom is different for each amino acid. In ∝-amino acids the amino group and the carboxyl group are attached to the same carbon atom. Amino acids can be classified as β Ɣ δ or ε based on the location of carbon atom to which the amino group is attached.

  Scarlet Skimmer ( Crocothemis servilia ) ( Female ) Clicked at Elephanta Caves. Scarlet Skimmer also known as Ruddy Marsh Skimmer is a species of dragonfly which belongs to the family Libellulidae. Distribution: It is native to east and southeast Asia. Identification: It is a medium sized blood-red dragonfly with a thin black line along the mid-dorsal abdomen. Its eyes are blood-red above and purple laterally. Abdomen with a narrow black mid-dorsal carina. Female have oblivaceous-brown thorax and abdomen. The black mid-dorsal carina is broad in female. It breeds in ponds, ditches, marshes and open swamps. Scarlet Skimmer Clicked at Elephanta Caves Previous post of Wildlife Series: Tricolour Pied Flat:  https://anaszoology.blogspot.com/2022/08/trocolour-pied-flat.html

Taxonomical categories/ranks represents the group of organisms sharing common characteristics/features. Example: Insects represents a group of organisms sharing common features like three pair of jointed legs. Taxonomical categories include Kingdom, Phylum (for animals) and Division (for plants), Class, Order, Family, Genus and Species. Kingdom is the highest taxonomical category and species is the lowest taxonomical category. To place an organism in a particular taxonomical category one must have a knowledge of the organisms characteristics.  Taxonomical Categories: 1) Kingdom: It is the highest taxonomical category. There are 5 Kingdoms: Animal, Plants, Fungi, Protista and Monera Different organisms are placed in different kingdoms based on their characteristics. Example: a) Organisms that are multicellular, do not possess chlorophyll, cell wall is absent in cell, and are eukaryotic are placed in the Kingdom Animalia. e.g. Human, fishes, frog etc. b) Organisms that are multicellular

 It is the most accepted model of Plasma Membrane/Cell Membrane. It was proposed by Singer and Nicolson in the year 1972. Phospholipids form bilayer in the centre. their unsaturated fatty acids forms the tail and glycerol forms the head, which prevents the close packing of the molecules. Phospholipids show two types of movements: Transition and Flip-Flop movement. Transition: Molecules change their position in the same layer. Flip-Flop: Molecules interchange between two layers. There are two types of proteins in cell membrane/plasma membrane Extrinsic/Peripheral proteins - Form 30% of the total membrane protein, superficial, easily removed, some are covered by glycolipids/glycoproteins. They provide structural and functional specificity to the membrane. eg. ATPase, spectrin, acetycholinesterase etc. Intrinsic/Integral Proteins - Form 70% of the total membrane proteins, embedded in lipid bilayer, can be extracted by rupturing membrane, held in position by polar and nonpolar side of phos

A) Danielli - Davson Model / Sandwich Model / P-L-P Model: This model of plasma membrane was proposed by Danielli and Davson in the year 1935. According to this the plasma membrane is trilaminar, where lipids bilayer is sandwitched between the two protein layers. Hence it is also called as P-L-P model (P=protein, L=lipid). This model fails to explain functional specificity and active transport through membranes. B) Unit Membrane Model / Robertson Model: This model of plasma membrane was proposed by Robertson in the year 1959. According to Robertson, all membranes have the same basic structure but they have their own distinctive composition. Example: Internal organelles have more proteins than lipids in eukaryotic cells whereas plants and bacteria have more lipids than proteins. This model fails to explain the membranes stability and permeability. Related Articles: 1) Biomembranes https://anaszoology.blogspot.com/2022/08/biomembranes.html

Tricolour Pied Flat ( Coladenia indrani ) Clicked at Nagla Block, Mumbai. The Tricolour Pied Flat is a butterfly belonging to the family Hesperiidae.  Distribution: Found in Sri Lanka, India, Myanmar. Identification: The upperside of the butterfly is bright golden-yellow forewing with a discal series of four semi-transparent white black-bordered spots, the first small and above the extremity of the cell, the second large quadrate and within the cell, the third elongate and beneath the latter, the fourth exterior to their juncture Underside blackish-brown suffused with golden-yellow, brightest on the hindwing: markings as above but more clearly defined. Importance of Butterflies: Butterflies act as pollinators. When they feed on nectar of the flowers their bodies collect the pollens from these flowers. These pollens are then carried to other plants which helps to produce new seeds. Majority of the plants in nature needs pollinators like butterflies to reproduce. Butterflies helps to ma

Biomembrane/Biological Membrane is a semipermeable covering around the cell and organelles, which separated them from the external environment. Biomembrane which covers the cell is called a cell membrane/Plasmalemma, biomembrane which covers the organelle is called subcellular membrane. Composition of Biomembrane Biomembranes are tripartite or trilaminar i.e. made up of three layers Proteins : 59-75% fibrous or globular proteins Lipids : 20-40 % Phospholipid, sterol, glycolipid, sphingolipid Carbohydrates : 1-5% Hexose, hexamine, sialic acid Functions of Biomembranes: Helps to transport the solutes across the membrane. Biomembrane only allow certain types of molecules to enter the cell and organelle, they keep the toxins from entering into the cell. The receptors present on biomembranes helps the cells to communicate.