Cell organelles and their functions and location

Structure:

• Consist of small (30S) and large (50S) ribosomal subunits
• Each subunit consists of ribosomal RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure and proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis.
• Present in the cytosol Cytosol A cell’s cytoskeleton is a network of intracellular protein fibers that provides structural support, anchors organelles, and aids intra- and extracellular movement. The Cell: Cytosol and Cytoskeleton, as part of RER, and in mitochondria

Function:

• Translation Translation Translation is the process of synthesizing a protein from a messenger RNA (mRNA) transcript. This process is divided into three primary stages: initiation, elongation, and termination. Translation is catalyzed by structures known as ribosomes, which are large complexes of proteins and ribosomal RNA (rRNA). Stages and Regulation of Translation of RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure and protein synthesis Synthesis Polymerase Chain Reaction (PCR)
• Protein folding Protein folding Processes involved in the formation of tertiary protein structure. Proteins and Peptides

Ribosomes (composed of a small and large subunit) translate mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure into a polypeptide chain by attracting tRNA tRNA The small RNA molecules, 73-80 nucleotides long, that function during translation (translation, genetic) to align amino acids at the ribosomes in a sequence determined by the mRNA (RNA, messenger). There are about 30 different transfer rnas. Each recognizes a specific codon set on the mRNA through its own anticodon and as aminoacyl trnas (RNA, transfer, amino Acyl), each carries a specific amino acid to the ribosome to add to the elongating peptide chains. RNA Types and Structure (which are tethered to amino acids Acids Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. Acid-Base Balance) with complementary anticodon Anticodon The sequential set of three nucleotides in transfer RNA that interacts with its complement in messenger RNA, the codon, during translation in the ribosome. Basic Terms of Genetics sequences.
tRNA tRNA The small RNA molecules, 73-80 nucleotides long, that function during translation (translation, genetic) to align amino acids at the ribosomes in a sequence determined by the mRNA (RNA, messenger). There are about 30 different transfer rnas. Each recognizes a specific codon set on the mRNA through its own anticodon and as aminoacyl trnas (RNA, transfer, amino Acyl), each carries a specific amino acid to the ribosome to add to the elongating peptide chains. RNA Types and Structure: transfer RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and StructureA site: aminoacyl siteP site: peptidyl site

mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure: messenger RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure

• Largest structure within the nucleus
• Made up of DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure, RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure, and proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis
• Functions:
  • Ribosome biogenesis
  • Formation of signal-recognition particles

Microphotography of the nucleus and nucleolus

• Protein complexes
• Contain enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes known as proteases Proteases Proteins and Peptides (break peptide bonds)
• Degrade unneeded or damaged proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis

• Microtubule-based cytoskeletal structures
• Responsible for movement and sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology functions
• Sperm use flagella Flagella A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called flagellin. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as cilia but are longer in proportion to the cell bearing them and present in much smaller numbers. Helicobacter for propulsion
• Epithelial cells use cilia for chemo-, thermo-, and mechanosensation.

Structure:

• Cylindrical organelle composed of the protein, tubulin Tubulin A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from sperm flagellum; cilia; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120, 000 and a sedimentation coefficient of 5. 8s. It binds to colchicine; vincristine; and vinblastine. Flucytosine, Griseofulvin, and Terbinafine
• Short microtubule triplets arranged in a cylinder 
• A bound pair of centrioles forms a centrosome Centrosome The cell center, consisting of a pair of centrioles surrounded by a cloud of amorphous material called the pericentriolar region. During interphase, the centrosome nucleates microtubule outgrowth. The centrosome duplicates and, during mitosis, separates to form the two poles of the mitotic spindle (mitotic spindle apparatus). Cell Cycle.

Functions:

• Cell division Cell Division A type of cell nucleus division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species. Cell Cycle (spindle formation in mitosis Mitosis A type of cell nucleus division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species. Cell Cycle)
• Cellular organization:
  • Anchoring the cytoskeleton Cytoskeleton The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm. The Cell: Cytosol and Cytoskeleton
  • Organization of microtubules Microtubules Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein tubulin and are influenced by tubulin modulators. The Cell: Cytosol and Cytoskeleton in the cytosol Cytosol A cell’s cytoskeleton is a network of intracellular protein fibers that provides structural support, anchors organelles, and aids intra- and extracellular movement. The Cell: Cytosol and Cytoskeleton and determination of spatial arrangement
• Production, arrangement, and function of cilia and flagella Flagella A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called flagellin. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as cilia but are longer in proportion to the cell bearing them and present in much smaller numbers. Helicobacter

Schematic diagram of centrioles: cylindrical organelles comprising microtubule triplets