Biology describing them as a nun house. Anton
Biology Notes 1. Organisms are made of cells that have similar structural characteristics. 1 Outline the historical development of the cell theory, in particular the contributions of Robert Hooke and Robert Brown. The development of the cell theory starts in the 1600? s with Robert Hooke? s discovery of cells when viewing a piece of cork under a microscope and describing them as a nun house. Anton van Leeuwenhoek was crucial in the development of microscopes making simple microscopes through advanced lens making techniques that enabled him to see 300X and also discovered bacteria.Robert Brown later in the 1900? s made the discovery of the cell nucleus.
2 Describe evidence to support the cell theory. 1. All living organisms are composed of one or more cells – Even in the smallest life form there is at least one cell 2.
Cells are the basic building block of life 3. All cells are derived from pre-existing cells – through the process of meiosis and mitosis 4. In a multicellular organism, the activity of the entire organism depends on the total activity of its independent cells 3 Signi? ance of technological advances to developments in the cell theory Assess the impact of technology including the development of the microscope on the development of the cell theory The development of cell theory has been heavily impacted by the improvement of technology. The improvement has allowed us from ? rst only seeing a big group of cells to being able to now see to a scale so small we can see in and around a single cell. This has allowed us to observe cells with more detail than ever before and allow us to more accurately determine what cells have what purpose and many other uses.
The cell theory states: • All living things or organisms are made of cells and their products. • New cells are created by old cells dividing into two. • Cells are the basic building units of life.
The development of the microscope was vital for all 3 points. Without the invention and founding of compound microscopes and electron microscopes as well as new stains and techniques to look at specimens discoveries such as ? new cells are created by old cells dividing into two? would not have been discovered.Therefore the invention of these new types of microscopes have made a huge positive impact onto the development of what we know a cell to be today. The microscope has improved from many different designs the three most prominent being, a single lensed microscope (First saw bacteria and life in water), a light microscope (discovered cells, nucleus, vacuole, etc.
) and the electron microscope (discovered nucleolus, ER etc. ) Each microscope discovered smaller and smaller parts to the original cell and allowed us to observe better quality at lower magni? ations. Computers and automated programs for microscopes have also improved the microscope to avoid human error. This improvement in microscopes was vital for the development of cell theory, because without being able to observe at a huge magni? cation through a screen we wouldn? t easily be able to observe changing cells and old cells dividing into two etc.
Stains such as iodine and new types of specimen presentation have also added to the development of cell theory and our understanding of cells.Stains like iodine allowing us to see chloroplast are a good example of how technology has improved our understanding, looking at different parts of specimens has also made our results more accurate with ? ndings like specialized cells looking different and their not only just being 1 set type of cell. Technology has de? ned the present day view and theory? s of biology. With improvements in microscopes allowing us to see smaller cells more clearly, gives us more of an exact idea of what is really in a cell.
Stains have also allowed us to see more parts of the cell and give us more information about what each part of the cell is for.Computers have also allowed us to record and share information with other biologist? s more quickly and ef? ciently providing a quicker and more ef? cient way of research. Technology has had a major positive in? uence on biology as a whole and especially regarding the cell theory. 4 Identify cell organelles seen with current light and electron microscopes 5 Describe the relationship between the structure of cell organelles and their function Organelle Nucleus Mitochondrion Ribosome Vacuole Chloroplast Description Round black dot, usually near the centre of the cell Oval with star? h inside, has 2 membranes Little balls on ER BIG thing in the middle Oval with Stacks of lines, like a drawing of a hurricane (thylakoids) Round sack – Contains digestive enzymes Fat wings, Stacked disks like pancakes. Like a mother ship Near the Nucleus, striped tubes (rough has ribosomes) Outside line of the cell Thin lipid bilayer, inside the cell wall Fluid of cell Function Brains or control centre of the cell Energy centre of the cell (cellular respiration) Protein synthesis (makes protein) Stores food, waste etc Photosynthesis Lysosome Golgi ApparatusDigestion Packages products for shipments to other cells Transports materials Endoplasmic Reticulum Cell Wall Cell Membrane Cytoplasm Provides rigidity and protection Controls entry and exit Site of many reactions 2.
Membranes around cells provide separation from and links with the external environment. 1 Identify the major groups of substances found in living cells and their uses in cell activities There are 2 main groups of chemical substances found in cells: Organic substances and inorganic substances. Organic Substances are substances made by living things.They contain carbon and hydrogen e. g.
Carbohydrates, Lipids, Proteins and Nucleic acids. Inorganic Substances are substances that do not contain carbon as the main element, except for carbonates, e. g. water, mineral salts. Chemical Component Lipids Description Contains carbon, hydrogen and oxygen and store energy. Energy is more dif? cult to release for cell use.
Breaks down into fatty acids Contains Carbon, Hydrogen, Oxygen, and nitrogen. Used in the cell for structure, storage, movement and transport of cells. Use Oil is lipids at room temp.Storage for the cell and major fuel Body growth, (cell growth) Cell Structure Proteins e. g. Gelatin Nucleic Acids DNA + RNA largest and most complex of the organic molecules.
Contains Carbon, Hydrogen and Oxygen. They (carbohydrates) are used in respiration, storage of energy and some for structural support. Its subunit? s product controls the function of the cell and the cell organism Respiration, storage of energy and some for structural support. Carbohydrates – Mono saccharide – disaccharide – polysaccharide (starch) Identify that there is movement of molecules into and out of cells For Any cell to work it has to function with its outside environment, this means that the cell needs to take in substances needed for them to work and to expel waste and other substances.
This movement happens through the cell membrane, the cell membrane is semi-permeable (letting some things in but not others, selectively) What goes in Gases (oxygen and carbon dioxide), Nutrients (sugars, amino acids, glycerol and fatty acids) and water What goes out Wastes (urea, uric acid and excess carbon dioxide) as well as mucus etc. Describe the current model of membrane structure and explain how it accounts for the movement of some substances into and out of cells. The current model for the cell membrane is called the ? uid mosaic model. In this model there is a double layer of lipids (fats) with their tails facing inwards. The membrane is thought to be quite ? uid, hence the title.
Proteins are scattered all throughout the structure. The heads are hydrophilic (water loving) but the tails are hydrophobic (water hating so they face each other) there is no hydrophobic head.Water and substances move through the integral protein, like a but cheek.
4 Compare the process of diffusion and osmosis Diffusion: the movement of any molecules from a region of high concentration to a region of low concentration of that substance, until equilibrium is reached. This does not require an energy input. Osmosis: the movement of water molecules from a region of high water concentration to a region of low water concentration through a selectively permeable membrane.It does not require an energy input. OSMOSIS Type of substances that move The movement of water molecules from a high concentration to a low one Movement along a concentration gradient DIFFUSION The movement of any type of molecule from a low concentration until equal Librium Movement along a concentration gradient None required No ACTIVE TRANSPORT The movement of molecules from a low concentration to a high concentration Movement against a concentration gradient Energy required YesConcentration gradient along which they move Energy Requirements Only across selectively permeable membranes? Examples None required Yes All plants and animals Cigarette smoke Tea Bag Perfume Uptake of glucose in intestine 5 Explain how the surface area to volume ration affects the rate of movement of substances into and out of cells.
A small cell has a large SA:V ratio and therefore can exchange molecules with it’s external environment rapidly. However, ions and water can be lost by diffusion and osmosis, and heat can be lost at a faster rate.A large cell has a small SA:V ratio and therefore exchanges molecules with it’s external environment slowly. Large cells are less efficient as often they cannot obtain enough oxygen and nutrients for their needs. 3. Plants and animals have specialized structures to obtain nutrients from their environment.
1 Identify some examples that demonstrate the structural and functional relationships between cells, tissues, organs and organ systems in multicellular organisms . Multicellular organisms (tree)Organ Systems (transport system, xylem) Organs (leaf) Tissues (phloem tissue) Cells (guard cells) Organelles (mitochondria) Molecules (lipids) Atoms (oxygen, hydrogen, carbon) 2 Distinguish between autotrophs and heterotrophs in terms of nutrient requirements. Autotrophs = Self feeding (all plants are self feeding) – Photosynthetic (Makes food) – Chemosynthetic (makes own chemicals) Heterotropes = Cannot make own food (all animals) 4 Identify the general word equation for photosynthesis and its role in ecosystemsC02 + Water -> O2 + CH2O (carbohydrate) Photosynthesis in our environment – Makes producers that form the food web, stuff eats producers predators eat them etc. – Other plants rely on glucose intake – Atmospheric gases essential to living organisms are recycled during photosynthesis, removes co2 gives o2 Mitosis Interphase – Total jumble Prophase – Moderate jumble Metaphase – nice bow Anaphase – condensed bundle Telophase – two groups Cytokinesis – two distinct shit like ? gures