Bio Content

Organelle

Organelle

A specialized structure within a cell that performs a specific function, such as the Golgi apparatus, mitochondria, and endoplasmic reticulum.

Cell Theory

A fundamental principle of biology stating that all organisms are composed of cells, all cells come from pre-existing cells, and the cell is the basic organizational unit of living things.

Prokaryotic Cells

Simple, usually unicellular cells that lack a membrane-bound nucleus and organelles, including bacteria and archaea.

Eukaryotic Cells

More complex cells that contain a membrane-bound nucleus and organelles, including plants, animals, fungi, and protists.

Plasma Membrane

A semipermeable structure that separates the interior of the cell from the external environment.

Cytoplasm

The gel-like substance within a cell that includes the cytosol and organelles, excluding the nucleus in eukaryotic cells.

Ribosomes

Non-membrane-bound structures that assist in protein synthesis.

Nucleoid

The irregularly shaped region in prokaryotic cells where the genetic material (DNA) is located.

Plasmids

Small rings of double-stranded DNA found in many prokaryotic cells, in addition to chromosomal DNA.

Organelles

Subcellular structures with specific functions, some of which are membrane-bound in eukaryotic cells.

Golgi Apparatus

An organelle that processes and packages proteins into vesicles for export from the cell.

Mitochondria

Membrane-bound organelles that release energy from organic compounds through cellular respiration.

Chloroplasts

Organelles found in plant cells that use light energy to produce glucose through photosynthesis.

Endoplasmic Reticulum (ER)

A network of membranous tubules and sacs involved in protein and lipid synthesis; includes rough ER (with ribosomes) and smooth ER (without ribosomes).

Biomolecules

Biological molecules, including proteins, nucleic acids, carbohydrates, and lipids, that are essential for life.

Proteins

Complex biomolecules made of amino acids that perform a wide range of functions in living organisms.

Carbohydrates

Organic compounds made of carbon, hydrogen, and oxygen, serving as energy sources and structural components.

Lipids

Hydrophobic organic molecules that include fats, oils, and phospholipids, playing roles in energy storage and membrane structure.

Enzymes

Proteins that act as biological catalysts, speeding up biochemical reactions by lowering activation energy without being consumed.

Amino Acids

The building blocks of proteins, linked by peptide bonds to form polypeptide chains.

Polypeptide

A chain of amino acids linked by peptide bonds, which folds into a functional protein.

Primary Structure

The linear sequence of amino acids in a polypeptide chain.

Secondary Structure

The folding or coiling of a polypeptide chain into structures such as alpha helices and beta-pleated sheets.

Tertiary Structure

The three-dimensional shape of a protein formed by further folding of the polypeptide chain.

Quaternary Structure

The arrangement of multiple polypeptide chains or prosthetic groups into a single functional protein.

Denaturation

The process by which a protein loses its functional shape due and tertiary structure due to environmental factors

Exocytosis

The process by which secretory proteins are exported from a cell by vesicle fusion with the plasma membrane.

Proteomics

large-scale study of the structure, function and interactions of proteins.

Proteome

is the complete set of proteins expressed by the genome

Amino Acid Structure

Cause for secondary structure of proteins

due to the formation of hydrogen bonds between the amine and carboxyl groups of amino acids within a polypeptide

Why does an A helix form

hydrogen bonds form between amine and carboxyl groups from non-adjacent peptide bonds within the polypeptide chain

Why does B pleated sheet form

Hydrogen bonds form between amine and carboxyl groups in different parts of adjacent polypeptide chains

Why does tertiary structure form

tertiary structure occurs due to different types of bonds, such as the disulfide bridge and the hydrogen bridge, between the R groups (side chains) of the amino acids

conjugated protein

A protein with a prosthetic group

Proteins for use in cell

Synthesised by free ribosomes in cytosol

Proteins for export

Synthesised by ribosomes on rough endoplasmic reticulum

Nucleic Acids

Organic biomolecules that store and transmit hereditary information; includes DNA and RNA.

DNA (Deoxyribonucleic Acid)

A double-stranded nucleic acid that carries genetic instructions for the synthesis of RNA and proteins.

RNA (Ribonucleic Acid)

A single-stranded nucleic acid involved in protein synthesis, with various forms including mRNA, tRNA, and rRNA.

Nucleotide

The basic building block of nucleic acids, consisting of a phosphate group, a five-carbon sugar, and a nitrogenous base.

Nitrogenous Bases

The components of nucleotides that include adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U).

Purines

Nitrogenous bases with a two-ring structure; includes adenine (A) and guanine (G).

Pyrimidines

Nitrogenous bases with a one-ring structure; includes cytosine (C), thymine (T), and uracil (U).

Complementary Base Pairing

The specific pairing of nitrogenous bases in DNA; adenine pairs with thymine (A-T) and guanine pairs with cytosine (G-C).

Phosphodiester Bond

The covalent bond that links nucleotides together in a nucleic acid strand.

5' End

The end of a nucleic acid strand that has a free phosphate group.

3' End

The end of a nucleic acid strand that has a free hydroxyl group.

Transcription

The process of synthesizing mRNA from a DNA template.

Translation

The process of synthesizing a polypeptide chain from mRNA at the ribosome.

mRNA (Messenger RNA)

A type of RNA that carries the genetic information from DNA to the ribosome for protein synthesis.

tRNA (Transfer RNA)

A type of RNA that brings amino acids to the ribosome during protein synthesis, matching them to the codons on mRNA.

rRNA (Ribosomal RNA)

A type of RNA that forms the core of ribosome's structure and catalyzes protein synthesis.

Codon

A sequence of three nucleotides on mRNA that codes for a specific amino acid.

Anticodon

A sequence of three nucleotides on tRNA that is complementary to a codon on mRNA.

Gene

A segment of DNA that contains the instructions for making a specific protein or functional RNA.

Exons

Coding regions of a gene that are expressed in the final mRNA product.

Introns

Non-coding regions of a gene that are removed during RNA processing.

Operon

A cluster of genes under the control of a single promoter, commonly found in prokaryotes.

Transcription Factors

Proteins that regulate the transcription of genes by binding to specific DNA sequences.

Microsatellite

A short repeated sequence of nucleotides found at a defined location (locus) on a chromosome.

DNA Sequencing

The process used to determine the order of the four nucleotide bases (adenine, thymine, guanine, and cytosine) in DNA.

Polymerase Chain Reaction (PCR)

A technique used for DNA amplification that makes millions of identical copies of a piece of DNA.

Gel Electrophoresis

A method used to separate and visualize nucleic acids and proteins according to their size.

DNA Polymerase

An enzyme that synthesizes multiple copies of target DNA during PCR and DNA sequencing.

Taq Polymerase

A heat-resistant DNA polymerase extracted from Thermus aquaticus, commonly used in PCR, due to it’s high optimum temp

Reverse Transcriptase

An enzyme that synthesizes single-stranded DNA using single-stranded RNA as a template.

RNA Polymerase

An enzyme that synthesizes RNA from DNA during transcription.

DNA Ladder

A molecular weight standard used in gel electrophoresis to estimate the length of DNA fragments.

Short Tandem Repeats (STRs)

Stretches of DNA sequences, usually 2-6 base pairs, that are repeated many times and vary between individuals.

DNA Profiling

A technique that compares and identifies individuals based on their unique DNA sequence.

Bacterial Transformation

The process of incorporating foreign DNA into a bacterial cell.

CRISPR-Cas9

A gene editing technology that can cut DNA at specific locations using a guide RNA and the Cas9 enzyme.

Transgenic Organisms

Organisms that have had genes from another species inserted into their genetic material.

Genetic Modification

The alteration of an organism's genetic material (DNA) using biotechnology.

Catalysis

The process of increasing the rate of a biochemical reaction without the enzyme being consumed.

Hydrophobic

Describes a non-polar molecule or part of a molecule that cannot dissolve in water.

Enzyme specificity

The ability of an enzyme to catalyze a specific reaction with a particular substrate.

Active site

The region of an enzyme where substrate molecules bind and undergo a chemical reaction.

Enzyme-substrate complex

The temporary complex formed when an enzyme binds to its substrate.

Lock-and-key model

A model describing how the active site of an enzyme and its substrate fit together precisely.

Induced-fit model

A model that describes how the active site of an enzyme changes shape to fit the substrate more closely upon binding.

Activation energy

The minimum energy required to initiate a chemical reaction.

Metabolism

The set of all biochemical reactions that sustain life, including catabolic and anabolic pathways.

Glycolysis

The first step in cellular respiration that breaks down glucose to produce energy.

Krebs cycle

A series of reactions in cellular respiration that generates energy through the oxidation of acetyl-CoA.

Electron transport chain

A series of protein complexes in cellular respiration that transfer electrons and produce ATP.

Cofactor

A non-protein component that assists an enzyme in catalyzing a reaction.

Coenzyme

An organic cofactor, that aids enzyme activity. may also transfer protons , electrons and/or chemical groups from one molecule to another.

ATP (Adenosine triphosphate)

The primary energy carrier in cells, providing energy for various biological processes.

NADPH

A coenzyme involved in photosynthesis, carrying electrons and protons for the synthesis of organic compounds.

Competitive inhibition

A type of enzyme inhibition where an inhibitor competes with the substrate for the active site.

Non-competitive inhibition

A type of enzyme inhibition where an inhibitor binds to an allosteric site, changing the enzyme's shape and function.

Feedback inhibition

A regulatory mechanism where the end product of a pathway inhibits an enzyme involved in its production.

Ribozymes

RNA molecules that can catalyze biochemical reactions, functioning as enzymes without proteins.

Biochemical Pathway

A series of chemical reactions that occur inside a cell.

Photosynthesis

The process by which plants and other photosynthetic organisms convert sunlight into chemical potential energy, often referred to as carbon fixation.

Rubisco

An enzyme that catalyzes the fixation of carbon dioxide in the Calvin cycle, crucial for photosynthesis.

Autotrophs

Organisms that produce their own organic compounds from inorganic substances, also known as producers.

Heterotrophs

Organisms that obtain organic compounds by consuming other organisms, also known as consumers.