Cell Biology and Cytology Lecture Notes

A set of vocabulary flashcards covering the structural, functional, and chemical components of cells, including organelles, membrane models, and cellular inclusions based on lecture.

Cytology

The study of cell form and structure.

Cell biology

The study of cell structure and function.

Father of cytology

Robert Hooke

Father of modern cytology

C. P. Swanson

Termed cytology

Hertwig

Cell Theory

Proposed by Schleiden (German Botanist) and Schwann (German Zoologist), stating that all living beings consist of cells and the cell is the smallest structural and functional unit of life.

Omnis cellula e cellula

A law proposed by Rudolf Virchow stating that cells are formed by pre-existing cells.

Coenocytic

A multinucleated condition resulting from multiple karyokinesis not followed by cytokinesis, as seen in Muco, Rhizopus, and Vaucheria.

Syncytium

A multinucleated condition resulting from the fusion of cells, as seen in striated muscles and bone marrow.

DNA:RNA ratio in prokaryotic cell

$$1:2$$

DNA:RNA ratio in eukaryotic cell

$$1:1$$

Chlamydia and Rickettsia

Organisms that have both DNA and RNA as nucleic acid and serve as the connecting link between virus and bacteria.

Akaryotic cell

Cells that lack a nucleus, such as mature mammalian RBCs (except Camel and Illama) and sieve tube cells.

Mesokaryotic cell

Cells that lack histone protein in DNA and a nucleolus in the nucleus, such as class Dinophyceae.

Organelles without membrane

Ribosome, nucleolus, centrioles, chromosomes, and cytoskeleton (microfilament and microtubule).

Organelles with double unit membranes

Plastid and mitochondria.

Transosomes

Triple membrane-bound structures found in the ovarian follicle of birds used for yolk synthesis (vitellogenesis).

Mitochondria nicknames

Power house of cell, electric house of cell, cellular furnace, ATP mills, and prokaryotic cell within eukaryotic cell.

Chloroplast nickname

Kitchen of the cell or photosynthetic apparatus.

Nucleus nicknames

Control centre of cell, Brain/Director of cell, or Principle of the cell.

Endoplasmic Reticulum (ER) nicknames

Endoskeleton of cell, working bench of cell, pipeline of cell, or membrane factory of cell.

Golgi body nicknames

Baker's body, lipochondrion, dictyosome, Dalton complex, idiosome, middle man of cell, or traffic police of cell.

Ribosome nicknames

Palade particles, protein factory of cell, or engine of cell.

Lysosome nicknames

House keeper, suicidal bag, atom bomb, scavenger of cell, or disposal unit.

Middle lamella

The outermost protective plant cell wall layer that connects four plant cells, composed mainly of $Ca$ pectate and $Mg$ pectate.

Phragmoplast

A precursor of the cell plate formed during cytokinesis by vesicles of Golgi bodies and spindle proteins.

Primary wall

A thin and elastic single layer found in all cells, made up of cellulose ($\beta$-D glucose).

Intusussception

The growth of the primary cell wall by the deposition of more substances over the existing layer.

Secondary cell wall growth

Known as Apposition, where growth occurs by the deposition of layers.

Plasmodesmata

Living cytoplasmic connections between two plant cells.

Desmosome

Connections between two animal cells.

Apoplasm

The non-living connection between plant cells.

Fluid mosaic model

The most accepted membrane model proposed by S. J. Singer and G. L. Nicolson, describing proteins as icebergs floating in a sea of lipid.

Ampipathic

A molecule with both a polar/hydrophilic head and a non-polar/hydrophobic tail, such as a phospholipid.

Flip-flop movement

The movement exhibited by phospholipids within the cell membrane.

Lomasome

An extracellular cell organelle found in fungi between the cell membrane and cell wall that helps in cell wall proliferation.

Protoplasm description

Termed by Purkinje and described by Huxley as the physical basis of life.

Tonoplast

The selectively permeable living membrane of a vacuole.

Anthocyanin

A water-soluble pigment inside cell sap that changes color based on pH (Red in acidic, Blue/Purple in basic).

Ribophorins

Proteins that help attach ribosomes to the Endoplasmic Reticulum.

Svedberg unit ($S$)

The measuring unit for ribosomes, representing the sedimentation coefficient.

Cristae

Infoldings of the inner mitochondrial membrane which serve as the structural unit of respiration.

Oxysomes

Also called elementary particles or $F_0-F_1$ particles; they are the functional units of respiration containing ATPase enzyme.

Semi-autonomous cell organelle

Organelles like mitochondria and plastids that can divide, synthesize some proteins, and contain their own 70S ribosomes and ds circular DNA.

Succinate dehydrogenase

The only Krebs cycle enzyme present in the inner membrane of mitochondria rather than the matrix.

Leucoplast types

Amyloplast (stores starch), Proteinoplast/Aleuroplast (stores protein), and Elaioplast/oleosome (stores lipids).

Chloroplast shapes

Cup-shaped (Chlamydomonas), Horse shoe shaped (Ulothrix), Star shaped (Zygnema), Spiral shaped (Spirogyra), Reticulate (Oedogonium), and Discoidal (Vaucheria).

Quantasome

The functional unit of photosynthesis located in the thylakoid, containing about 230 chlorophyll molecules.

Endomembrane system components

ER, Golgi body, Lysosome, and Vacuole.

Rough ER (RER)

A region of the ER originating from the nuclear envelope, containing ribosomes, and responsible for protein synthesis (glycosidation).

Smooth ER (SER)

A region of the ER responsible for lipid synthesis (glycosylation), steroid hormone synthesis, and detoxification.

Acrosome

A structure in sperm cells formed by the Golgi bodies.

Primary lysosome

Newly formed lysosomes from the RER and Golgi bodies that contain only enzymes.

Peroxisomes

Microbodies that contain catalase for $H_2O_2$ breakdown and glycolic acid oxidase for photorespiration.

Glyoxisome

The largest microbody, common in germinating oily seeds, which converts fats to carbohydrates via the glyoxylate cycle.

Sphaerosome

Known as the plant lysosome, it is involved in lipid or oil synthesis (lipogenesis).

NOR (Nucleolar Organizing Region)

The specific region on chromatin where the nucleolus is attached.

Chromonemata

Thin, coiled, double genetic parts of the chromosome.

Centromere

The primary constriction of a chromosome where spindle fibers attach during cell division.

Metacentric chromosome

A chromosome with the centromere in the middle, appearing V-shaped during anaphase.

Sub-metacentric chromosome

A chromosome with the centromere near the center, appearing L-shaped during anaphase.

Acrocentric chromosome

A chromosome with the centromere away from one end, appearing J-shaped during anaphase.

Telocentric chromosome

A chromosome with the centromere at one end, appearing I-shaped.

Inulin

A reserve carbohydrate found in Dahlia roots composed of fructose monomers.

Alkaloids

Nitrogenous, water-insoluble, poisonous waste products of protein metabolism, such as Quinine, Nicotin, and Caffeine.

Quinine

An alkaloid obtained from Cinchona bark used for Malaria.

Reserpine

An alkaloid obtained from Rauwolfia serpentina roots used for snake bites.