Cytology and Cell Biology Practice Flashcards

A comprehensive set of vocabulary flashcards covering cytology, cell organelles, biochemistry, genetics, and metabolic processes based on the provided lecture notes.

Nucleus

The cell's control center that contains genetic material and participates in cell division.

Nucleoplasm

The substance within the nucleus that surrounds the chromatin and nucleolus.

Chloroplast

A double-membranous organelle that provides photosynthesis by utilizing thylakoids and stroma.

Mitochondria

Double-membranous organelles that carry out aerobic respiration and the synthesis of lipids.

Rough Endoplasmic Reticulum (RER)

A membranous organelle involved in secretory protein production, phospholipid assemblage, and glycoprotein production.

Smooth Endoplasmic Reticulum (SER)

An organelle responsible for the synthesis of lipids, metabolism of carbohydrates, storage of calcium ions, and detoxification of drugs and poisons.

Golgi body (complex)

A single-membranous organelle responsible for the modification, packaging, storage, and transport of molecules, as well as the synthesis of cell wall components.

Lysosome

A single-membranous organelle containing enzymes for intracellular digestion, autophagy, and autolysis.

Peroxisomes

Single-membranous organelles that protect the cell from radicals formed during metabolic processes and take part in the metabolism of cholesterol and fatty acids.

Central vacuole

A large plant cell organelle that maintains tonicity, stores inorganic ions like $K^+$ and $Cl^-$, and isolates harmful substances.

Ribosomes

Non-membranous organelles consisting of large and small subunits that serve as the site for protein synthesis.

Cytoskeleton

A network of microfilaments, intermediate filaments, and microtubules responsible for cell movement, contraction, and division.

Centrioles

Non-membranous organelles responsible for microtubules assemblage and chromosome separation.

Capsule

A sticky carbohydrate layer in prokaryotic cells that helps the cell stick to surfaces and hide from immune systems.

Nucleoid

The region in a prokaryotic cell that holds genetic blueprints without a protective membrane.

Plasmid

Small DNA molecules in prokaryotes that often carry genes for antibiotic resistance.

Transformation

A type of genetic recombination where a donor cell releases a piece of DNA and a recipient cell actively takes it up.

Conjugation

Genetic recombination involving the transfer of DNA between bacterial cells in direct contact.

Transduction

The process by which a piece of DNA is transferred from a donor to a recipient cell by a virus.

Chemoautotrophs

Bacteria that obtain energy by oxidizing inorganic substances, such as Nitrosomonas and Nitrobacter.

Primary structure of proteins

The unique sequence of amino acids formed by peptide bonds during translation, exemplified by insulin and hemoglobin.

Secondary structure of proteins

Protein structures formed by hydrogen bonds resulting in coils called alpha helices or fold-backs called beta-pleated sheets.

Tertiary structure of proteins

A globular protein shape formed by bonds between amino acid radicals, such as disulphide, ionic, and hydrophobic bonds.

Quaternary structure of proteins

The association of two or more polypeptide chains, such as in hemoglobin or immunoglobulins.

Saturated fat

Fats with no double bonds in their structural formula, typically solid at room temperature.

Unsaturated fat

Fats containing one or more double bonds in their structural formula, typically liquid at room temperature.

Amylopectin

A substance in starch made of many $1,4$ linked $\alpha$-glucose molecules with branches formed by $1,6$ linkages.

Cellulose

The structural part of plant cell walls consisting of $\beta$-glucose units linked by glycosidic bonds.

Enzyme

Globular protein macromolecules that act as catalysts to speed up chemical reactions without being consumed.

Competitive Inhibitor

A substance that competes with the substrate for the same active site on an enzyme, which is a reversible process.

Fluid Mosaic Model

A description of membrane structure where phospholipids and proteins move by diffusion, creating a mosaic pattern.

Phagocytosis

A form of endocytosis where a cell engulfs hard particles of food to form a food vacuole.

DNA Polymerase

An enzyme that forms phosphodiester bonds between nucleotides in the $5'$ to $3'$ direction.

RNA Polymerase

The enzyme that unwinds DNA and adds nucleotides to a growing RNA transcript during transcription.

Okazaki fragments

Short DNA segments synthesized discontinuously in the $5'$ to $3'$ direction on the lagging strand template.

Degenerate Code

A property of the genetic code where some amino acids are specified by several different triplets.

Rubisco

The enzyme that catalyzes carbon dioxide fixation by attaching $CO_2$ to Ribulose-1,5-bisphosphate ($RuBP$).

Glycolysis

The metabolic pathway where glucose is oxidized into two pyruvates, yielding a net of $2$ ATP and $2$ NADH.

Krebs Cycle

The mitochondrial matrix process that oxidizes acetyl-CoA to produce $2$ ATP, $6$ NADH, $2$ FADH_2, and $4$ CO_2 per glucose molecule.

Oxidative Phosphorylation

The process of ATP formation resulting from the transfer of electrons from NADH or FADH_2 to oxygen via the electron transport chain.

Crossing-over

The exchange of genetic material between two homologous chromosomes during Prophase I of meiosis.

Chiasmata

The points where homologous chromosomes hold together and exchange genetic material during meiosis.

Binary fission

A type of asexual reproduction used by protozoans and prokaryotes involving simple division of the mother cell into two daughter cells.

Spermatogenesis

The process of male gamete production where diploid spermatogonia undergo meiosis to produce four haploid spermatozoa.

Oogenesis

The process of female gamete production initiated in the embryo and arrested at Prophase I until ovulation.

Morula

A second stage of embryogenesis consisting of a solid ball of $16$-$32$ tightly packed blastomeres.

Blastula

A hollow sphere of cells with a fluid-filled cavity called a blastocoel, formed during early embryonic development.

Gastrula

An embryo stage characterized by the reorganization of the blastula into layers, including the ectoderm, mesoderm, and endoderm.