BIOSCI 101 Definitions Flashcards
Nucleoid
Concentrated DNA
Ribosomes
Synthesise Proteins
Capsule
Jelly-like Coating
Flagella
Locomotion
Fimbriae
Attachment to other bacteria
Eukaryotic Cells
Have a nucleus which contains most of the cell’s DNA
Nucleus
Organelle containing genetic material
Endoplasmic Reticulum
Network of membranous tubules continuous with the nuclear membrane
Golgi Apparatus
A complex of vesicles and folded membranes
Lysosomes
An organelle containing degradative enzymes enclosed in a membrane
Mitochondria
Organelle responsible for cellular respiration
Chloroplast
A plastid in green plant cells which contains chlorophyll and in which photosynthesis takes place
Cytoskeleton
Interconnecting protein structures within the cytoplasm
Cilia and Flagella
Tiny, hair-like organelles
Thylakoids
Flattened sacs inside a chloroplast
Microtubule
Microscopic tubular structure
Microfilament
A small rod-like structure
Intermediate Filaments
Cytoskeletal components found in the cells of vertebrate animal species
Homogenization
A process that involves breaking apart cells - releasing organelles and cytoplasm
Homogenate
A suspension of cell fragments
Centrifugation
A process which involves the application of the centrifugal force for the sedimentation of heterogeneous mixtures with a centrifuge
Macromolecule
A polymer constructed of identical or similar building blocks called monomers
Lipids
Insoluble in water but soluble in organic solvents
Phospholipids
A class of lipids that are a major component of all cell membranes
Polysaccharides
A carbohydrate whose molecules consist of a number of sugar molecules bonded together.
Chitin
Polymer of glucose
Proteins
Link carboxyl group of one amino acid to amino group of the next
Channel Protein
A protein that allows the transport of specific substances across a cell membrane
Carrier Protein
A protein that transports specific substance through intracellular compartments
Transport Proteins
A protein that serves the function of moving other materials within an organism
Exocytosis
The contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane
Endocytosis
The taking in of matter by a living cell by invagination of its membrane to form a vacuole
Monomer
A molecule that can be bonded to other identical molecules to form a polymer
Fluid Mosaic
A flexible layer made of lipid molecules is interspersed with large protein molecules that act as channels through which other molecules enter and leave the cell
Amphipathic
Having both hydrophilic and hydrophobic parts
Glycoprotein
Carbohydrate groups attached to the polypeptide chain
Desmosomes
Two adjacent cells are attached, formed from protein plaques in the cell membranes linked by filaments
Connexins
Structurally related transmembrane proteins that assemble to form vertebrate gap junctions
Hydrophylic
Having a tendency to mix with, dissolve in, or be wetted by water
Hydrophobic
Tending to repel or fail to mix with water
Peptide Bonds
A chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O)
Amino Acid
A simple organic compound containing both a carboxyl (—COOH) and an amino (—NH2) group
Alpha Helix
A righthand-coiled or spiral conformation
Beta Pleated Sheet
Beta strands (also β-strand) connected laterally by at least two or three backbone hydrogen bonds
Globular
Composed of Globules
Polypeptides
Chains of amino acids
Chaperonin
A protein that aids the assembly and folding of other protein molecules in living cells
Hydrolysis
The chemical breakdown of a compound due to reaction with water
Renaturation
The conversion of denatured protein or nucleic acid to its native configuration
Anabolic
The synthesis in living organisms of more complex substances from simpler ones
Catabolic
The breaking down in living organisms of more complex substances into simpler ones
Enzyme
A substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction
Cofactor
A substance (other than the substrate) whose presence is essential for the activity of an enzyme
Allosteric
Alteration of the activity of an enzyme by means of a conformational change induced by a different molecule
Prokaryote
DNA is in nucleoid not enclosed by membrane
mRNA
A large family of RNA molecules that convey genetic information from DNA to the ribosome
tRNA
An adaptor molecule composed of RNA
Anticodon
A sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA
Codon
A sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule.
Helicase
Enzymes which break H-Bonds and untwist double helix at replication fork
Primer
A short strand of RNA or DNA that serves as a starting point for DNA synthesis
Telomeres
A compound structure at the end of a chromosome
Histones
Any of a group of basic proteins found in chromatin
Transcription
Transfers of information from DNA into messenger RNA
Translation
Nucleotide sequence of mRNA translated into the amino acid sequence of a protein
Exons
Sequence which will leave the nucleus mRNA. The coding segment will be translated into amino acid sequences
Introns
Non-coding RNA which lies between exons
snRNPs
Small nuclear ribonucleoproteins
P Site
Holds tRNA carrying the growing polypeptide chain
A site
Holds the tRNA carrying the next amino acid to be added
E Site
Where discharged tRNAs leave the ribosome
Gene
Region of DNA which codes for a functional product, either a polypeptide or an RNA molecule
Mutations
Changes in one or a few nucleotides in a sequence can affect protein structure and function (small scale)
Chromatin
DNA packed with proteins
Heterochromatin
Highly condensed DNA
Enchromatin
Less condensed DNA
Acetylation
A reaction that introduces an acetyl functional group into a chemical compound
Methylation
The addition of a methyl (CH3) group to the DNA strand itself
Epigenetics
The study of changes in organisms caused by modification of gene expression
Tryptophan
An α-amino acid that is used in the biosynthesis of proteins
Operon
A group of genes coding for proteins with related functions
Promoter
A region of DNA that initiates transcription of a particular gene
Repressor
A substance which acts on an operon to inhibit enzyme synthesis
Inducer
A molecule that regulates gene expression
Activator Protein
DNA-binding proteins that bind to enhancers or promoter-proximal elements
Palindromic Sequence
A nucleic acid sequence on double-stranded DNA or RNA wherein reading 5’ (five-prime) to 3’ (three prime) forward on one strand matches the sequence reading 5’ to 3’ on the complementary strand with which it forms a double helix
Plasmid
A circular autonomously replicating DNA molecule which can replicate inside a host bacterial cell
Recombinant DNA
Genes/DNA from two different sources are combined in vitro into the same molecule.
Restriction Enzymes
Cut DNA at specific sequences 4-8 bp in length.
Cloning Vectors
DNA molecule that can carry foreign DNA
Selectable Markers
A gene introduced into a cell, especially a bacterium or to cells in culture, that confers a trait suitable for artificial selection.
Gel Electrophoresis
A laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size.
Transcriptome
Part of the genome transcribed into RNA.
Central Dogma
Coded genetic information is transcribed into individual transportable cassettes, composed of messenger RNA (mRNA).
Allele
Alternative versions of a gene.
Homozygous
Identical alleles for a character (PP)
Heterozygous
Different alleles for a character (Pp)
Genotype
An organism’s genetic makeup (PP, Pp or pp)
Phenotype
An organism’s expressed traits (purple or white flowers).
Locus
Position on a chromosome.
