BIO MODULE 1 AND PLANTS

• All living organisms are composed of cells or are product of cells (viruses)
• All cells are produced from pre existing cells
• Cells can clone themselves
• Prokaryotic cells


  • Simple
  • Small
  • Unicellular (bacteria)
• Prokaryotes


  Organisms that DO NOT have membrane bound organelles (nucleus)
• Components of prokaryotic cells

  • Nucleoid (contains genetic material)
  • Plasmid (contains non-essential genes)
  • Fimbriae (hair structure to help stick to other cells)
  • Capsule (sticky protein layer to evade immune system or stick to surfaces)
  • Flagella (for movement)
• Types of archaea


  • Halophiles (live in salty places)
  • Thermophiles (live in hot environments)
  • Methanogens (produce methane)
• Eukaryotic cells


  • Complex
  • Larger
  • Multicellular (plants, animals, fungi)
• Eukaryotic cell


  Cell which contains organelles (nucleus, mitochondria etc.)
• Endosymbiont theory


  Mitochondria and chloroplast were once prokaryotes as a form of association of 2 or more bio species
• DNA is located in the nucleus as well as in the chloroplast and mitochondria but their own
• Enzymes are found on the membranes including cell membranes which means the membranes are directly involved in cellular respirations
• The type of biochemical reactions process that occurs depends on the nature of internal membrane, arrangement of internal membrane, presence of specific enzymes, and environmental factors
• Mitochondria


  Also known as "powerhouse of the cell" as it produces energy. The outer membrane gives its shape which allows small substances in and out. The inner membrane known as matrix, contains its own DNA and enzymes which makes it easy to make copies of itself
• Ribosomes


  Present in cytoplasm and attached to rough endoplasmic reticulum. They consist of RNA and proteins. They carry out genetically coded instructions of DNA to produce, and proteins are necessary for cell function and its structure. Newly synthesised proteins pass from ribosomes into the ER, where protein is folded. FOUND IN BOTH PROKARYOTIC AND EUKARYOTIC
• Vacuoles


  Present in both plant and animal cells. In plant cells vacuoles are large with fluid sacs in cytoplasm. The single membrane known as tonoplast encloses the watery solution (cell sap). Cell sap contains substances such as mineral salt, sugars and amino acids dissolved in water (may contain pigments that give cell colour). In animal cells, vacuoles are small and act as storage for organs
• Cell membrane


  Present in all cells. The purpose of the membrane is to enclose all the other organelles such as the cytoplasm and nucleus. It's essentially an outer covering which supports and protects the cells. It also controls the movement of substances in and out the cell
• Cytoplasm


  Thick, clear, jelly like substance present inside the cell membrane. Most of the chemical reactions take place within the cytoplasm. Cell organelles including ER, vacuoles, mitochondria and ribosomes are all present in cytoplasm
• Nucleus


  Stores the information needed to control all cell activities. The nucleus contains DNA which is passed from one generation to another. The nucleus is surrounded by a double nuclear membrane which consists of tiny pores which regulates the passage between the nucleus and cytoplasm
• Endoplasmic reticulum


  There are two types of ER (smooth and rough). Rough ER is called rough because it has ribosomes attached to its surface. Soft is just smooth. They both have the same membrane but different shapes. Rough ER are folded bumpy sheets and soft ER look more like tubes. ER consist of a transportation network of substance like the metabolism of carbohydrates, lipids, steroids and proteins
• Golgi bodies


  Made of flat membranes but differ from ER as ribosomes aren't attached. Gogis process, package and sort cell products. The membrane surrounds an area of fluid where the complex molecules (proteins, sugars, enzymes) are stored and changed. Golgis are involved in the transportation of materials in and out the cell
• Lysosomes


  Protect the cell by engulfing the foreign bodies entering the cell and help in cell renewal. Therefore it is known as the cell's sucide bag. They break down excess or worn out cell parts. They may also be used to destroy invading viruses and bacteria. Lysosomes can help cells self-destruct if damaged
• Chloroplasts


  Organelles that contain the green pigment, chlorophyll. Chloroplasts are responsible for photosynthesis "production of sugar with the use of sunlight". The stroma is the fluid inside the chloroplast and contains enzymes, ribosomes and its own DNA. Unlike mitochondria, the membrane isn't folded in stacks and chlorophyll is found on these membranes called thylakoids
• Cell wall


  Provides support and protection for the cell. They are only found in plant cells. Cell walls lie on the outside of the cell membrane
• Cell membrane


  Composed of two layers (bilayer) of phospholipids represented by a head and two tails. The head is known as hydrophilic and the fatty acid tails are hydrophobic. A lipid called cholesterol is scattered among the phospholipids to make the membrane flexible (liquid). Protein molecules are scattered in the bilayer to form channels that allow some materials to cross the membrane, some proteins are fixed and some move freely
• Types of membrane proteins

  • Transport proteins (act like passageways which allows specific molecules to move across the membrane)
  • Receptor proteins (respond to certain signals like hormones)
  • Recognition proteins (glycoproteins that identify the cell and are called antigens or marker molecules)
• Light microscope


  Cannot magnify beyond 1500X due to the lack of resolution. Staining techniques is used to enhance contrast to obtain quality images. Magnification up to 1500 X and resolution up to 200 nm
• Fluorescence microscope


  Similar to LM but produces specific images of specific parts of cells. FM shows structures beyond the limit of resolution, fluorescent substance/ dye is used. Sample is illuminated by a high intensity source of light that causes the fluorescent substance produces light
• Transmission electron microscope (TEM)

  Electrons pass the resin/sample. 2D image is produced and shows finer details within. Heavy metals are used to stain structures within the cell. Maximum magnification is 1.5 million X and resolution is 2 nm
• Scanning electron microscope (SEM)


  Image is produced by scanning the surface with a focused beam of electrons. Electrons interact with atoms in the sample, producing various signals that contain information about the composition of the sample. 3D images are produced, super detailed. Electron beam DOESN'T PASS THROUGH, rather scattered. Resolution is 10nm
• Microscope skills


  • Field of view (diameter of specimen)
  • Magnification (makes image appear bigger)
  • Resolution (distinguish between objects)
• Calculating cell size


  1. Size of cell= diameter of field of view divided by cells that fit across

  2. Image size divided by magnification= actual cell size

  3. Image size divided by actual size= magnification

  4. Magnification times actual size= image size
• Solvent


  Substance able to dissolve other substances
• Solute


  Substance which dissolves in a solvent. Example: Sugar (solute) is dissolved in water (solvent) to make a sugar solution
• Dilute solution


  Contains only a small amount of solute
• Concentrated solution


  Contains a large amount of solute
• Higher concentration


  More particles
• Low concentration


  Less particles
• Diffusion


  Movement of any type of molecule from a high to a low concentration until equilibrium is met. Both solute and solvent can move
• Net movement of particles

  Rate of diffusion