Ch.7 Flashcards
Who was Robert Hooke?
First person to use a light microscope and saw chambers in it(called them cells)and therefore discovered cells;his discovery stimulated other scientists to search for cells in other living things
What is the cell theory?
- All living things are made of cells
- Cells are the basics unit of structure and function in living things
- New cells are produced from living cells
What are all the cell parts?
Membrane-thin,flexible barrier
Wall-strong layer around the cell membrane and has the same function a the membrane
Nucleus-center of the cell and contains the cells genetic material and controls the cell activities
Cytoplasm-gel like substance that fills the cell(not the nucleus)
What are the two cell categories?
Prokaryotes-no nucleus,have cytoplasm and a membrane,carry out every activity associated with life(bacteria)
Eukaryotes-have a nucleus,plants animals and fungi are examples,have cytoplasm and membrane,contain several specialized structures called organelles,have endoplasmic reticulums
What are organelles?
Collective Name given to the cell parts;spec listed organs or structures
What is cytoplasm?
Portion of the cell outside the nucleus;works together with the nucleus;one of the tow major parts in a eukaryotic cell
What does the nucleus contain?
Nearly all of the DNA in a cell;it’s also coded which instructions for making proteins and other important molecules
What is the nickname of the nucleus?
Control center
What is the nuclear envelope?
Surrounds the nucleus;composed of two membranes and has thousands of nuclear pores which allows materials to move in and out of the nucleus
What is chromatin?
Consists of DNA bound to protein;granular like material you see in the nucleus;
What happens when a cell divides chromatin?
Condense ps to form chromosomes(genetic material passed on from one cell to the next)
What is the nucleolus?
Small,dense region found in most nuclei;where the assembly of ribosomes begins
What are ribosomes?
Produce proteins;found throughout the cytoplasm;made of RNA
What is an endoplasmic reticulum?
The site where lipid components of the cell membrane are assembled,along with other proteins materials exported from the cell
What is the rough ER?
Chemically synthesizes proteins that are to be exported;ribosomes are found on its surface
What is the smooth ER?
Contains collections of enzymes that form special tasks
What is the Golgi apparatus?
Discovered by Italian scientist Camilo Golgi;modifies,sorts,and packages proteins and other materials from the ER for storage in the cell or secretion outside the cell;proteins are the shipped to their final destination in the cell from here(FACTORY)
What are lysosomes?
Small organelles filled with enzymes;one of its functions is t o breakdown lipids,carbohydrates,and proteins(removes junk)
What is the vacuole?
Stores materials such as salt,water,carbohydrates,and proteins;most cells have one single,central vacuole filled with lipid;the pressure of the central vacuole is to make it possible for plants to support heavy structures such as leaves an flowers
What is the mitochondria?
Organelles that convert the chemical energy stored in food into compounds that are more convenient for cell use;enclosed in two membranes
What are chloroplasts?
Organelles that convert light energy into chemical energy;contains the green pigment chlorophyll(plays a key role in the photosynthetic process)
What is the cytoskeleton?
Network of filaments that helps maintain the cell shape;involved in the cell movement;the filaments it has are microfilaments and microtubules
What is a lipid bilayer?
The core of the cells membranes that is a double layer sheet;gives embarked a tough,flexible structure that forms a strong barrier the cell’s surroundings
What is co concentration?
The mass of a solute in a given volume of a solution
What are cell walls made up of?
Cellulose(fiber in our diet)
What is a key factor about membranes and walls?
They are porous so stuff can travel through it
What else do membranes do?
Maintain a stable environment
What is passive transport?
Process that does not require energy to molecules from HIGH TO LOW concentration
What are the types of passive transport?
Diffusion-movement of SMALL particles across a selectively permanent membrane like the cell membrane until equilibrium is reached(equal distribution)(HIGH TO LOW)
Facilitated diffusion-movement of LARGE molecules through the cell membrane,but need help(protein channel made from protein)
Osmosis-diffusion of water through a selectively permeable membrane like a cell membrane(HIGH TO LOW)
What are the types of solutions p?
Hypertonic-solutions that contain high C of solute relative to another solution(cell shrivels when placed in because water diffuses from it)
Hypotonic-solutions that contain low C solute relative to another solution(cell swells when placed because water diffuses in the cell)
Isotonic-solution that contain same C of solute as another solution(cell stays the same because water comes in and out at the same rate. The fluid that surrounds the cell is isotonic)
What is active transport?
Movement of molecule from LOW TO HIGH concentration and this movement requires energy
What are protein pumps?
Proteins that work as pumps(DUH)
What is Endocytosis and exocytosis?
The mechanism by which very large molecules(food and wastes)get into an out of the cell(endo in;exo out)
What is a unicellular organism?
One cell
What is a multicellular organism?
Many cells;specialized to perform particular functions within the organism
What are the levels of organization in a cell?
(In a multicellular organism)
- Individual cells
- Tissue
- Organs-many tissues that work together
- Organ systems-groups of organs
Who was Anton van Leeuwenhoek?
First person to see organisms in water;first to use a microscope to study nature
