Biology: a Tour of the Cell

Name: Period: Biology: A Tour of the Cell  A ______is the smallest unit of life.  They can vary in size, shape and function (______determines function).  The light ______led the way to knowledge of the cell. Microscopes:  A ______microscope magnifies objects (specimens) ~1000x their size. Most cellular structures ______be seen. o You will work with a light microscope in the lab.  ______microscopes give more detail and magnify a million times the object’s size. o However, the organism ______when using an electron microscope. There are 2 types of electron microscopes:  A ______electron microscope (SEM) gives a ______image of a specimen/object.  A ______electron microscope (TEM) transmits ______to view the interior of an object. A history lesson:  Robert ______(1665) named the ______after looking at cork under the microscope.  Anton ______(LAY-von-hohk) (1670’s) developed a simple light microscope & discovered ______organisms and called them “little beasties”.  Rudolf ______(1855) stated that all cells came from pre-existing ______(a.k.a. Cell Theory). The Cell Theory (Virchow) has 3 basic principles:  ______are the basic units of life.  All organisms are made of ______cells.  All cells arise from ______cells.

Cell Structures: Name: Period: Note: Not all of these are in your text! Order is not the same.  All cells have an enclosure called a cell, or ______membrane. o This functions as the ______and controls what enters and exits the cell. o It is mainly composed of ______and proteins.  Within the cell is the ______. This is a semifluid substance that contains the organelles.  The ______are small structures that have specific functions within the cells.  The ______is a protein network within the cytoplasm that helps support the cell and helps the cell maintain or change its shape. It also o ______organelles o Enables the cell to ______o Allows materials to move throughout the cell o Composed of ______& microfilaments  The ______is the control center of the cell o It is surrounded by the nuclear envelope o It contains the ______. There are ______chromosomes in the human nucleus (in every cell of the human body). The chromosomes are the ______(genetic material).  The nucleus is only found in______cells!  The nucleus contains the ______(if more than 1, nucleoli). o Nucleolus: makes ______ Ribosomes  make proteins. 2 Types of Cells Prokaryotic Cells  ______ ______organelles (membrane-bound structures) Name: Period:  Contained w/in cell membrane & cell wall, contain ribosomes, 1 ______chromosome in ______(NO nucleus) & ______(extra pieces of DNA) Eukaryotic Cells  Protists, Fungi, ______, & ______ Contained w/in cell membrane (may have a cell wall)  Contain ______& other membrane-bound organelles  Means ‘______’ There are 2 types of cells: 1. Prokaryotes: These are bacteria (in Kingdom ______).  They are ______organisms.  These were the ______cells. They are very small cells and are very simple cells. 2. Eukaryotes: found in all other kingdoms except Monera.  These have a nucleus (as well as a cell membrane and the majority of the organelles being discussed, depending on the type of organism).  Ribosomes make ______from amino acids; can be found suspended within the cytoplasm or attached to the endoplasmic reticulum. (not really organelles; these are cellular components)  The ______(ER) is a network of membrane that produces materials for the cell. There are 2 types: o The ______ER contains ribosomes and functions in protein synthesis and makes new cell membrane. o The smooth ER makes ______, process carbohydrates and breaks down ______.  The ______apparatus is composed of flat membranous save that modify, package and distribute molecules (warehouse of the cell).  Vacuoles are membrane-bound organelles that have various functions. o Some ______food, water, proteins, ions, or wastes. Generally these are ______and centralized. Name: Period:  ______contain digestive enzymes that break down large molecules and old organelles that the cell no longer needs.  ______, double-membrane-bound organelles, perform photosynthesis. o This is the process of making ______(synthesis) in the presence of ______(photo). o Plants (some bacteria & protists) make their own food (a.k.a. ______).  The ______is the “powerhouse of the cell” b/c it changes stored enter from food into useable chemical energy (______) for chemical reactions. o ATP = adenosine triphosphate (energy ‘______’ of cells) o The chemical reactions are ______. Cellular Structures

 ______are short hair-like projections that are in the surface on the cell usually in large number. (NOT organelles) o Beat in ______and aid in the cell’s movement or in the movement of fluid over the cell.  Flagella are long ______projections that are on the surface of the cell. (NOT organelles) o Usually 1 to 3 of these. o In prokaryotic cells, they spin like ______. o In eukaryotic cells, they move like ______. Plants differ from animal cells. In plants:  A cell ______surrounds the cell membrane.  The cell wall is a rigid outer covering that protects and maintains the ______of the plant cell.  Fungi, algae (a type of protist) and bacteria also have cell walls but the composition is different.  Plants ______lysosomes. Name: Period:  Animals are ______, meaning they must consume food. Animal cells:  ______a cell wall but have cytoskeletons for structural support.  ______chloroplasts  Contain small vacuoles (instead of a large centralized one)  Have ______BOTH Animal and Plant Cells Contain:

 Organelles previously mentioned (nucleus, ER, mitochondria, ER, ribosomes, etc)  ______ ______(in chromosomes) Cell/plasma membrane is composed of a ______(2 layers of phospholipids) with proteins interspersed.

 Phospholipids have a ______head & hydrophobic ______ Fluid & flexible Membrane Functions  Cell membranes are ______. This means that some things pass through the membrane while others cannot pass through (this depends on the ______& ______of the molecule).  Passive transport is the movement of a substance across a membrane ______energy input.  Active transport is the movement of a substance across a membrane ______the input of energy.  Concentration=[ ].  Molecules move from a ______[ ] gradient to a ______[ ] gradient.  A [ ] gradient is the difference between the [ ] of a particular molecule in 1 area and its [ ] in an adjacent area. Name: Period:  The rate of diffusion depends on ______and ______of molecules involved (molecules move faster at higher temperatures and smaller molecules move faster than larger molecules).  Once molecules are dispersed evenly, ______is reached and diffusion stops. Passive Transport  ______is the movement of molecules from a higher concentration to a lower concentration.  Facilitated diffusion is the diffusion of molecules with the help of a ______protein embedded within a cell membrane.  Osmosis is the diffusion of ______.  Diffusion, facilitated diffusion and osmosis are all type of passive transport. These do ______require energy (occur spontaneously).

Active transport in cells usually occurs with the help of ______but ______energy. An example is the sodium-potassium pump (Na+/K+ pump).

When comparing 2 solutions with a membrane between them, there are 3 types of solutions:

 ______: the fluid outside a cell has a higher [solute] than the cytoplasm inside the cell. In this case, water diffuses out of the cell.  Isotonic: the [solute] outside the cell= the [solute] inside the cell. In this case, no osmosis will occur.  ______: the fluid outside a cell has a lower [solute] than the cytoplasm inside the cell. In this case, water will move inside the cell. Bulk Transport: 1. ______: exo=exit; cyto=cell  Wastes and cell products are packaged in vesicles by the golgi apparatus.  The vesicles fuse with the cell membrane and leave the cell 2. ______: endo=within; cyto=cell  A portion of the cell membrane surrounds a substance outside of the cell & pinches off to form a vesicle Name: Period:  The vesicle moves inward and fuses with other organelles  This includes o Pinocytosis: cell ______o Phagocytosis: cell ______