BIO 023 Finals

• Cytology is the study of cell.
• Cell is the basic unit of organisms/building blocks of life.
• Nucleus is the cell’s control center.
• Nuclear envelope (outer, inner and nuclear pores) is the gateway to the nucleus.
• Outer membrane of the nucleus has ribosomes.
• Inner membrane of the nucleus has lamin proteins which are responsible for the disassembling and reforming of nuclear envelope during mitosis, the positioning of nuclear pores and programmed cell death known as apoptosis.
• Lamins provide critical barriers against genome instability in the nuclear envelope.
• Nuclear pore is the passage of molecules in or out of the nucleus.
• Chromatin (DNA and Histone) form the chromosomes, the gene bearers.
• Euchromatin is the transcriptionally active form of chromatin.
• Heterochromatin is the transcriptionally silent form of chromatin, examples include Barr bodies, one of the X chromosomes, human genes 1, 9and16.
• Nucleolus is for rRNA synthesis.
• The mRNAs transcribed in the nucleus pass out of the nuclear membrane and attached in the rough endoplasmic reticulum.
• The tRNAs and rRNAs are structural molecules that have roles in protein synthesis; however, these RNAs are not themselves translated.
• In eukaryotes, pre-rRNAs are transcribed, processed, and assembled into ribosomes in the nucleolus, while pre-tRNAs are transcribed and processed in the nucleus and then released into the cytoplasm where they are linked to free amino acids for protein synthesis.
• Nucleoplasm suspends the chromatin and it is where tRNAs are synthesized.
• Cytosol is the components of the cytoplasm which is mainly composed of water and is also known as the groundplasm, intracellular matrix (ICF) or cytoplasmic matrix.
• Inclusion is a non-living and so there is NO metabolic activity; storage of nutrients, minerals and metabolic secretions and excretions.
• Organelles are living and are active in metabolic activities.
• Cell is the basic unit of organisms/building blocks of life.
• Rough Endoplasmic Reticulum (RER) is a filamentous membranous organelle with ribosomes.
• Nucleus is the cell's control center.
• Nuclear envelope (outer, inner and nuclear pores) is the gateway to the nucleus.
• Outer membrane has ribosomes.
• Some of the proteins synthesized here by the mRNAs are for lysosomal enzymes and membrane of membrane bounded organelles (eukaryotes) while some are excreted out (vesicles) via the plasma membrane thru the process of exocytosis.
• Inner membrane has lamin proteins which are responsible for the disassembling and reforming of nuclear envelope during mitosis, the positioning of nuclear pores and programmed cell death known as apoptosis.
• Ribosomes are large (60s) and small subunits (40s); composed of rRNA and proteins; found in RER and cytoplasmic cytosol; sites of protein synthesis.
• Lamins provide critical barriers against genome instability in the nuclear envelope.
• Nuclear pore is the passage of molecules in or out of the nucleus.
• SER in the liver converts glycogen into glucose (glycogenolysis).
• Chromoplasts have carotenoid pigments that allow different colours that you see in leaves and fruits.
• Peroxisomes have powerful enzymes such as catalase, oxidase and metabolic enzymes so they have a profound breaking down capacity.
• The enzyme glucose-6-phosphatase present in SER takes parts in gluconeogenesis by converting glucose-6-phosphate to glucose.
• Lysosomes are suicide bags that contain hydrolytic enzymes classified into the types of substrate; proteinases (protein), nucleases, lipases and glucosidases.
• Cytochrome p540 enzymes are produced in the liver and are necessary in some catabolic activities, hormone synthesis and detoxification of drugs and other toxins.
• Amyloplasts are the greatest among all three and they store and synthesize starch.
• Leucoplasts are the non-pigmented organelles which are colourless and are usually found in most of the non- photosynthetic parts of the plant like roots.
• ER of muscle cells are called sarcoplasmic reticulum.
• Gerontoplasts are chloroplasts that go with the ageing process.
• Elaioplasts help in storing fats and oils that are needed by the plant.