Top1-Ch1-P1-6 Flashcards
Features of Living Organisms?
- High degree of chemical complexity and microscopic organisation.
- Systems for extracting, transforming and using energy from the environment.
- Defined functions for each of an organism’s components and regulated interactions among them.
- Mechanism for sensing and responding to alterations in their surroundings.
- A capacity for precise self-replication and self-assembly.
- Capacity to change over time by gradual evolution.
Plasma membrane?
Composed of lipid and protein molecules that form tough, thin, pliable, hydrophobic barrier around the cell. Barrier to free passage of inorganic ions and most other charged or polar compounds. Transport proteins in plasma membrane allows passage of certain ions and molecules.
Plasma Membrane picture
Cytoplasm and cytosol?
The cytoplasm is the internal volume enclosed by the plasma membrane. The cytoplasm contains an aqueous gel-like substance (called cytosol) and a variety of suspended particles with specific functions.
Cytosol contains what?
- Enzymes and RNA molecules that encode them.
- Components - (amino acids and nucleotides) from which these macromolecules are assembled.
- Metabolites -(the intermediates and products of metabolism).
- Coenzymes - (compounds essential to many enzyme-catalyzed reactions.
- Ribosomes - (sites of protein synthesis).
- Proteasomes - (degrade proteins no longer needed by the cell).
Enzymes?
Enzymes are large biological molecules responsible for the thousands of chemical interconversions that sustain life. They are highly selective catalysts, greatly accelerating both the rate and specificity of metabolic reactions, from the digestion of food to the synthesis of DNA.
Enzyme picture
Ribosome?
The ribosome is a large and complex molecular machine, found within all living cells, that serves as the primary site of biological protein synthesis. Ribosomes link amino acids together in the order specified by messenger RNA (mRNA) molecules.
Proteasomes?
Proteasomes are protein complexes inside all eukaryotes and archaea, and in some bacteria. In eukaryotes, they are located in the nucleus and the cytoplasm. The main function of the proteasome is to degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that carry out such reactions are called proteases. Proteasomes are part of a major mechanism by which cells regulate the concentration of particular proteins and degrade misfolded proteins.
All cells have, for at least some part of their life, either a _____ or a _____ , in which the genome - the complete set of genes, composed of DNA - is stored and replicated.
Answer: nucleus or a nucleoid
Nucleoid explain and compare to nucleus?
The nucleoid (meaning nucleus-like) is an irregularly-shaped region within the cell of a prokaryote that contains all or most of the genetic material. In contrast to the nucleus of a eukaryotic cell, it is not surrounded by a nuclear membrane.
Eukaryote?
an organism whose cells contain complex structures enclosed within membranes. The nucleus is enclosed within a double membrane, the nuclear envelope. The nucleoid in bacteria and archaea is not separated from the cytoplasm by a membrane.
Prokaryote?
Are a group of organisms whose cells lack a cell nucleus (karyon). The organisms whose cells do have a nucleus are called eukaryotes. Most prokaryotes are unicellular organisms, although a few such as myxobacteria have multicellular stages in their life cycles or create large colonies like cyanobacteria.
Prokaryotes include two major classification domains: the bacteria and the archaea.
Picture below: Cell structure of a bacterium, one of the two domains of prokaryotic life.
Name three distinct domains of life?
- *Bacteria** - inhabits soils, surface waters and tissues of other living or decaying organisms.
- *Archaea** - inhabit extreme environments. ie salt lakes, hot springs, highly acidic bogs and ocean depths
- *Eukarya** - animals, fungi, molds, plants, flagellates etc.
- *Note**: Eukarya and Archaea evolved from the same branch
Energy and carbon sources for all organisms?
All organisms
Under all organisms are - Phototrophs (energy from light) and Chemotrophs (energy from oxidation of chemical fuels)
Under Phototrophs - Autotrophs (carbon from CO2) and Heterotrophs (carbon from organic compounds).
Example of autotrophs are cynobacteria and vascular plants; and of heterotrophs are purple bacteria and green bacteria.
Under Chemotrophs - Lithotrophs (inorganic fuels) and organotrophs (organic fuels).
Example of lithotrophs are sulfur bacteria and hydrogen bacteria; and of organotrophs are most bacteria, all nonphototrophic and eukaryotes.
Bacteria cell main components?
- *Ribosomes** - protein synthesis from a RNA message.
- *Nucleoid** - contains a single, simple, long circular DNA molecule.
- *Pili** - provide points of adhesion to surface of other cells.
- *Flagella** - Propel cell through its surroundings.
- *Cell Envelope** - structure varies with type of bacteria
Animal cell parts?
- *Ribosomes** - protein synthesising machines.
- *Peroxisome** - oxidises fatty acids.
- *cytoskeleton** - supports cell, aids in movement of organelles.
- *Lysosome** - degrades intracellular debris unique to animal cells
- *Transport Vehicle** - shuttles lipids and proteins between ER, Golgi, and plasma membrane.
- *Golgi complex** - processes, packages, and targets proteins to other organelles or for export.
- *Smooth Endoplasmic reticulum (SER)** - site of lipid synthesis and drug metabolism.
- *Nucleus** - contains the genes (chromatin).
- *Nucleolus** - is site of ribosomal RNA synthesis.
- *Rough endoplasmic reticulum (RER)** - site of much protein synthesis.
- *Mitochondria** - oxidises fuels to produce ATP.
- *Plasma membrane** - separates cell from environment, regulates movement of materials into and out of cell.
- *Nuclear envelope** - segregates chromatin (DNA + protein) from cytoplasm
Plant cell parts?
Ribosomes - protein synthesising machines.
Peroxisome - oxidises fatty acids.
cytoskeleton - supports cell, aids in movement of organelles.
Transport Vehicle - shuttles lipids and proteins between ER, Golgi, and plasma membrane.
Golgi complex - processes, packages, and targets proteins to other organelles or for export.
Smooth Endoplasmic reticulum (SER) - site of lipid synthesis and drug metabolism.
Nucleus - contains the genes (chromatin).
Nucleolus - is site of ribosomal RNA synthesis.
Rough endoplasmic reticulum (RER) - site of much protein synthesis.
Mitochondria - oxidises fuels to produce ATP.
Plasma membrane - separates cell from environment, regulates movement of materials into and out of cell.
Nuclear envelope - segregates chromatin (DNA + protein) from cytoplasm
Cell Wall - provides shape and rigidity; protects cell from osmotic swelling
Glyoxysome - contains enzymes of the glyoxylate cycle
Plasmodesma - provides path between two plant cells
Vacuole - degrades and recycles macromolecules, stores metabolites
Thylakoids - site of light driven ATP (transports chemical energy) synthesis
Starch granule - temporarily stores carbohydrate products of photosynthesis
chloroplast - harvests sunlight, produces ATP and carbohydrates.
