cells

• Asexual reproduction:

  • Performed by a single unicellular organism
  • Daughter cells are clones
  • Examples include mitosis (cell division for growth of multicellular organisms and repair of their tissue) and binary fission (a specialized type of mitosis for unicellular organisms)
• In asexual reproduction, "budding" is when a new organism develops from an outgrowth due to cell division at a particular site (e.g., hydra)
• In vegetative reproduction, a new plant grows from a fragment of the parent or from a specialized reproductive structure
• Fragmentation is when an organism is split into pieces, each becoming a new individual
• Sexual reproduction:

  • Requires two parents of the same species
  • Results in genetically unique offspring through the combination of genetic material
  • The process is called conjugation for unicellular organisms
  • Sex cells known as gametes are produced by meiosis
• Cellular respiration:

  • Nutrients must be processed to access energy
  • Different cells use different methods of cellular respiration to produce energy
  • ATP (Adenosine triphosphate) is the energy currency of cells
  • Aerobic respiration (eukaryotic cells) involves mitochondria producing ATP from glucose and oxygen
• Anaerobic respiration (prokaryotic cells) occurs without mitochondria and generates ATP more slowly
• Organisms fall into categories based on oxygen requirements for cellular respiration:

  • Obligate aerobes require oxygen
  • Obligate anaerobes require an oxygen-free environment and perform fermentation instead of cellular respiration
  • Facultative anaerobes like yeast can switch between cellular respiration and fermentation depending on environmental conditions
• The need for nutrients:

  • There are three fundamental strategies for obtaining nutrients: autotrophic, chemosynthetic autotrophs, and heterotrophic
• Autotrophic organisms produce their own nutrients using environmental energy:

  • Photosynthetic autotrophs contain chlorophyll molecules that absorb sunlight to generate sugar through photosynthesis
  • Chemosynthetic autotrophs harness the energy released by inorganic chemical compounds
• Heterotrophic organisms rely on ingesting or absorbing nutrients:

  • Some single-celled organisms ingest food particles by endocytosis
  • Organisms like fungi break down their food externally through digestion and absorb the nutrients directly through their cell membrane
• Basic cell types:

  • Prokaryotic cells lack a nucleus and membrane-bound organelles
  • Eukaryotic cells have a nucleus containing DNA and membrane-bound organelles
• Cell theory:

  • All living things are made of one or more cells
  • The cell is the basic unit of structure for all living organisms
  • Cells only arise from pre-existing cells
• Discovery of Cells:

  • Anton van Leeuwenhoek and Robert Hooke were key figures in the discovery of cells and the development of microscopy
• MICROSCOPE PARTS

  • A microscope consists of various parts like the arm, objective lenses, stage clip, fine adjustment knob, coarse adjustment knob, rheostat, eyepiece, body tube, revolving nosepiece, objective lenses, stage, iris diaphragm, light source, and base
• Cell membrane - A thin layer that surrounds the cell and regulates what enters or leaves the cell.
• Mitochondria produce energy for various cell functions through the process of cellular respiration.
• The nucleus contains DNA that stores genetic information and controls cell activities.
• The nucleus is the control center of the cell, containing DNA.
• The lysosomes contain enzymes that break down waste materials and cellular debris within the cell.
• The ribosomes are responsible for protein synthesis within the cell.
• The nucleus is the control center of the cell, containing DNA.
• The cytoskeleton provides structural support and helps maintain the shape of the cell.
• Cytoplasm - The jellylike substance inside the cell where most chemical reactions take place.
• Nucleus - Contains genetic material (DNA) and controls cell activities.
• Ribosomes synthesize proteins using instructions provided by messenger RNA (mRNA).
• Cytoplasm contains enzymes responsible for chemical reactions within the cell.
• Ribosomes synthesize proteins using instructions provided by mRNA molecules.
• Mitochondria - Responsible for producing energy through respiration.
• Chloroplasts contain chlorophyll and are responsible for photosynthesis in plant cells.
• Cytoplasm is the fluid substance inside the cell where chemical reactions occur.
• Chloroplasts contain chlorophyll and are found in plant cells to carry out photosynthesis.
• The Golgi apparatus modifies and packages proteins and lipids produced by the endoplasmic reticulum.
• Lysosomes are membrane-bound organelles that contain digestive enzymes used to break down food particles and other substances.
• Endoplasmic reticulum (ER) is a network of flattened sacs or tubules involved in the production and transport of lipids and proteins throughout the cell.
• The plasma membrane regulates the movement of substances into and out of the cell.
• Vacuoles store water, nutrients, or waste products.
• microscope parts: stage stage is where the slide is placed slide is where the specimen is placed eyepiece lens is where the specimen is viewed
• Magnification = objective lens x ocular lens