Chapter 3: Cells Flashcards
Cells
Are the basic structure and functional units of living organisms
Vary in size, shape, and function
The three main parts of the cell
Plasma membrane, cytoplasm, nucleus
Plasma membrane
Forms boundaries of cell, it separates intracellular from extracellular fluid
The plasma membrane Structure Consist of a Byler of fluid_______ (98%) Within which are variety of proteins(___%)
Lipids, 2%
In the plasma membrane the
Phospholipids have ____%
Cholesterol have ___%
Glycolipids have ____%
75%, 20%, 5%
Bilayers
2 layers
Phospholipid molecules are arranged in two layers called
Bilayers
Phospholipid molecules have polar ______and nonpolar _____.
Heads, tails
Hydrophilic
Water absorbing
Hydrophobic
Water fearing
Phospholipid molecules heads face _____ sides, where their tails pointing towards ____
Both, each other
True or false
The plasma membrane functions as a selectively permeable barrier that regulates the flow of materials into and out of the cell
True
The two types of protein membranes
Integral(transmembrance) proteins, and peripheral membrane proteins
Integral proteins
Extend through the phospholipid bilayer
Peripheral membrane proteins
Are associated loosely with only one side of the membrane
Remember protein functions
Transporters,
Receptors for chemical messengers, enzymes that catalyze reactions, markers in cell recognition
anchors to sell cytoskeleton
Permeable
Membrane Is permeable to substances that can pass through it
Impermeable
A membrane is impermeable to substances that can’t pass through it
Cell membranes are selectively permeable which means
allows some things to pass more easily than others
Membranes are usually permeable to _______, uncharged, and small molecules
Non polar
A membrane is usually impermeable to
Ions, charged or Polar molecules
What is the exception for membrane permeability?
Water
Membrane transport
The variety of ways to transfer a substance across a membrane
Membrane transport-passive processes
Substances move down from their concentration gradients with no energy required from the cell. (High to low)
Membrane transport-Active processes
Energy is required to move substances against their concentration gradients or for substances otherwise unable to pass. (Low to high)
Passive transport-Diffusion
The net movement of molecules from an area of high to an area of low until equilibrium is reached
The rate of diffusion is affected by
Temperature, particle size, gradient, surface area, distance
The two types of diffusion
Simple, facilitated
Diffusion-simple
Non-polar and lipid soluble substances diffuse directly through the lipid bilayer
Eg.Fat soluble vitamins ADEK
Diffusion-Facilitated
Polar and charged molecules require transmembrane proteins as carriers, or use ion channels to move through the lipid bilayer
Eg.Glucose, amino acids, ions
Passive transport-osmosis
Net movement of water from an area of high water to an area of low water through a semi permeable membrane, until equilibrium is reached
Osmotic pressure
Ability of a solution to attract or draw and water
In osmotic pressure the greater the number of solute particles in the solution, the greater the osmotic pressure. This means
More water you have
Active transport
Substances across the membrane by moving against their concentration gradient and energy is required
Primary active transport
Energy from ATP hydrolysis changes the shape of a transporter protein and it “pumps” a substance across the membrane
Secondary active transport
Coupled transport of two molecules using energy supplied by an ion gradient, Maintained by a primary active transport pump.
Eg. Na+ is co transported with glucose
What is used to drive other substances into the cell for active transport?
The energy stored in Na+ or H+ concentration gradient
Vehicle Active transport
Used for large particles, macromolecules, and fluids
The two parts of vesicle transport?
Exocytosis, and endocytosis
Exocytosis
Moves a packaged vesicle out of the cell by fusing with the cell membrane and releasing its contents
Eg. Hormones, neurotransmitters
Endocytosis
Moves material into the cell by forming a vesicle
Eg. Phagocytosis
Cytoplasm
Cellular material between the plasma membrane in nucleus
Two elements of the cytoplasm
Cytosol and organelles
Cytosol
Is the fluid surrounding organelles, makes up at 75-90% of water with dissolved and suspended components
It’s the site for many chemical reactions required for cell s xistence
Organelles
Specialize structures that have specific functions necessary for the life of the cell
Most organelles are membrane bound
Organelles include
Mitochondria, ribosome, endoplasmic reticulum, Golgi complex, lysosomes, cytoskeleton
Mitochondria is inherited from
Yo mama
The mitochondria-function
Produces most ATP cells
A liver still has approximately how many ATP
1700
Ribosomes
Involved in proteins synthesis, tiny organelles composed of RNA and protein (not membrane bound)
Endoplasmic reticulum-function
Site of lipid and steroids synthesis and detoxifies drugs
Smooth endoplasmic reticulum
Continuation of rough endoplasmic reticulum but lacks ribosomes
Rough endoplasmic reticulum
Has ribosomes attached to external surface
Golgi complex
Modify sort package proteins from various destinations in the cell
Lysosomes
Digest substances transported into the cell or digest cellular debris
How are lysosomes formed
By the Golgi complex
What organelle has the digestive enzyme in it?
The Lysosome
Cytoskeleton
Provide structure and support, also aids in movement of structures within the cell
The nucleus
It’s bound by a double membrane, most cells have single nucleus, usually found near the center, contains jelly like nucleoplasm
Example of something with no nucleus
Mature red blood cell
Example of a Multinucleate
Skeletal muscle cells
Three regions or structures of nucleus
Nuclear envelope, nuclei, chromatin
Nuclear envelope
Double membrane that controls movement of substances between the cytoplasm and nucleus,
outer membrane is continuous with the RER
Lipid bilayer similar to the Plasma membrane
Nuclear poor
Circular ring of protein extending nuclear envelope. Allows for movement between cytoplasm and nucleus
Nucleoli
To produce ribosomes, not enclosed by membrane,
dark staining around structures found in nucleus
Nucleolus is
Singular
Nucleoli is
Plural
Chromatin
Thread like material composed of DNA and proteins of a non-dividing cell.
Function-consists of jeans which controls cellular structure and direct cellular functions by providing instructions for proteins synthesis
Cell division
Process by which cells reproduce themselves
The two types of cell division
Somatic and reproductive
Somatic cell division
Body cells undergo nuclear division to produce new body cell this is mitosis
Reproductive cell division
Germ cell undergoes nuclear division to produce gamete this is meiosis
Cytokinesis is _______ from mitosis and meiosis
Separate
Cytokinesis
Usually accompanies nuclear division
Both types of cell division involve ______ of events divided into _____
Orderly series, phases
cytoplasm
cellular material between the plasma membrane and the nucleus
what are the 2 elements of a cytoplasm
cytosol and organelles
cytosol
the fluid surrounding organelles
75-90% water with dissolved and suspended components
site for many chemical reactions required for cell exsistence
organelles
specialized structures with specific functions necessary for the life of the cell
most organelles are membrane bound
organelles include
mitochondria ribosome endo. r golgi complex lysosomes cytoskeleton
mitochondria is inherited from
your mother
mitochondria function
produce most atp cells
