Unit 3: Preparation Flashcards
What types of cells are plants, animals, fungi, and protists made out of?
Eukaryotic Cell (They have a nucleus)
What is the size comparison between plant and animal cells?
In general, plant cells are larger than animal cells.
What distinguishes plant cell and animal cells?
Their cell wall and chloroplasts
What is a the function of a peroxisome in a plant?
A membrane bound vesicles containing enzymes that convert fatty acids in seeds to sugars and held the cell use carbon dioxide during photosynthesis
What does the peroxisome provide in a plant?
Created sugars to provide a useable food source for germinating plants
What is a central vacuole in a plant and what is its function?
A very large membrane bound fluid storage sac that gives added internal support to a plant cell and stores water and other molecules
What is a chloroplast in a plant and what is its function?
A plastic that gives green plants their color and converts the energy in sunlight into stored energy in carbohydrates during photosynthesis
What is a plastid?
Organelle used to synthesize or store food
What I actin filaments do in plant cells?
Form the cytoskeleton
What is included in the nucleus?
Nuclear Pore
Chromatin
Nucleolus
Nuclear Envelope
What is a cell wall and what is its function?
A rigid structure surrounding the cell membrane that protects and supports the cell and allows materials to pass to and from the cell membrane through pore
What is a cell membrane?
A structure that separates the cell interior from the outside world and controls the movement of materials into and out of the cell
What is the cytoplasm?
A gel like material consisting mostly of water that contains dissolved materials and creates the chemical environment in which the other cell structures work
What is the nucleus and what is its function?
The command center of the cell that contains the DNA blueprints for making proteins and is surrounded by a double membrane to protect the DNA from from potentially damaging byproducts of biochemical reactions
What are nuclear pores and what is their function?
Pores in the nuclear membrane large enough to allow macromolecules to enter and ribosomes to leave the nucleus
What is chromatin?
Uncoiled chromosomes (DNA)
What is a nucleolus?
A specialized area of chromatin inside the nucleus responsible for producing ribosomes
What are ribosomes and what are their function?
Tiny 2-part structures found throughout the cytoplasm that help put together proteins
What is endoplasmic reticulum?
A system of flattened membrane bound sacs and tubes continuous with the outer membrane of the nucleus that has two types of membrane
What is different about rough ER?
It is studded with ribosomes and synthetic proteins
What is the function of smooth ER?
It synthesizes phospholipids and packages macromolecules in vesicles for transport to other parts of the cell
What is the Golgi Apparatus?
A stack of flattened membrane bound sacs that receives vesicles from the ER.
What is the function of the Golgi Apparatus?
Recieve vesicles from the ER, contains enzymes for modifying proteins and lipids, package finished products into vesicles for transport to the cell membrane and within the cell as lysosomes
What is the Mitochondrion?
The powerhouse of the cell where organic materials, usually carbohydrates, are broken down inside a double membrane to release and transfer energy
What receives vesicles from the ER?
The Golgi Apparatus
What is a Lysosome?
A membrane bound vesicle filled with digestive enzymes that can break down worn-out cell components or materials brought into the cell
What is a Peroxisome?
A membrane bound vesicle containing enzymes that break down lipids and toxic waste products like alcohol
What is a centrosome?
An organelle located near the nucleus that organizes the cells the cell’s microtubules and helps to organize the even distribution of cell components when cells divide
What is Vesicle?
A small membrane bound transport sac
What is a Vacuole?
A large membrane -bound, fluid filled sac for the temporary storage of food, water, or waste products
What is a cytoskeleton?
A network of three kinds of interconnected fibres that maintain cell shape and allow for movement of cell parts: actin filaments, intermediate filaments, and microtubules
What does the cytoskeleton allow for the movement of?
Actin filaments, intermediate filaments, and microtubules
What is the purpose of the cell membrane?
It separates the internal environment of a cell from its external environment
What are cell membranes composed of?
A double layer of phospholipid molecules
What are lipids?
Organic compounds that do not dissolve in water ex. Fats, oils, steroids like cholesterol
How does each part of a phospholipid molecule react with water?
The head end dissolves easily in water while the tail end is insoluble in water
What are the heads of a phospholipid exposed to?
Because they are on the outside, they are exposed to watery fluid outside and inside the cell
How permeable is the cell membrane?
It is selectively permeable
What does selectively permeable mean?
It allows some molecules to pass through while preventing others from doing so
What is diffusion?
The natural movement of molecules or ions from a region where they are more concentrated to one where they are less concentrated
Does diffusion require energy?
No, it is passive
What does it mean when something moves down the concentration gradient?
It is the natural tendency of a substance to from an area of high concentration to an area of low concentration
What is a gradient?
A general term that refers to a difference in quality between 2 regions
What is intracellular fluid?
Water inside the cell
What extracellular fluid?
Water outside the cell
What is osmosis?
The diffusion of a solvent (water) across a semi-permeable membrane that separates 2 solutions
What does it mean if a cell is isotonic?
If water concentration inside the equals water concentration outside the cell.
What does it mean if a cell is hypotonic?
If water concentration outside the cell is greater than that inside the cell, water moves into the cell
What does it mean if a cell is hypertonic?
If water concentration inside the cell is greater than that outside the cell, water moves out of the cell
Why can’t the cell membrane prevent the movement of water?
Because it is permeable to water molecules
Why do some molecules need special transfer proteins to get in and out of the cell?
They may be too large
What makes transport proteins selective?
The structure.
What criteria do transport proteins use to allow molecules to use them?
It’s shape, size, and electrical charge
What do carrier proteins help to move across the cell membrane?
They will only accept a non-charged molecule with a specific shape
What do channel proteins help move across a membrane?
They transport charge particles
What must a molecule have to pass through a channel protein?
It must be small enough to fit through the tunnel and have the right charge
What gets repelled in channel proteins?
Like a magnet, positively charges proteins repel positively charged ions
What are the 2 types of transport proteins?
Carrier protein
Channel protein
What is active transport?
Using energy to enable a cell to take in a substance that is more concentrated inside the cell than outside the cell
Where does energy for active transport come from?
ATP Adenosine TriPhosphate
What happen when one of 3 phosphates are split from ATP in a chemical reaction?
Energy is released that is harnessed to perform a cellular function
What is endocytosis?
When a cell membrane folds inward, trapping and enclosing a small amount of matter from outside the cell
What are the 3 forms of endocytosis?
Pinocytosis
Phagocytosis
Receptor assisted endocytosis
What is Pinocytosis?
The intake of a small droplet of extracellular flood along with any dissolved substance or tiny particles it may contain
What is phagocytosis?
The intake of a large droplet of extracellular fluid, often including bacteria or organic matter
Which type of cell does phagocytosis take place?
This occurs in specialized cells, such as white blood cells in our immune system
What is receptor-assisted endocytosis?
The intake of specific molecules that attach to special proteins in the cell membrane
What do the membranes of receptor assisted proteins contain that are special to them?
A uniquely shaped cavity that fits the shape of one specific molecule
What is exocytosis?
The process of removing substances from the cell
What happens in exocytosis?
A vesicle from inside the cell moves to the cell surface and fuses with the cell membrane. It then secretes the contents into the extra cellular fluid
