Studied by 8 peopleplasma membrane
boundary between cell and its environment it allows things in or out of the cells and allows the cell to maintain homeostasis
selectively permeable
allows some molecules in but not others and only in certain amounts
examples of molecules that pass freely
water, glucose, O2, gas, CO2
example of molecules that are regulated
proteins, all ions (Na+, CI-), large molecules
Stucture of Plasma Membrane
composed of a phospholipid bilayer; two fatty acid tails which are non-polar and phosphate head which is polar
fluid mosaic model
model of the plasma membrane; fluid bc its flexible and mosaic bc there are so many proteins that are embedded in the membrane
choloesterol
found in the Plasma membrane to help stabilize the phospholipids and prevents them from sticking together
transport proteins
act like tunnels and assist molecules moving in and out
passive transport
diffusion through the plasma membrane that requires no energy
Diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration
Osmosis
Diffusion of water through a selectively permeable membrane; water will always move until its equal on both sides
solute
substance being dissolved
solvent
substance doing the dissolving
isotonic solution
concentration of water in the cell is equal to the water outside the cell
hypotonic solution
concentration of solute is lower outside the cell; causes cell to swell
hypertonic
concentration of solute is greater outside the cell than inside; causes cell to shrivel
facilitated diffusion
type of passive transport where substances cross the PM through a protein channel because they are polar
types of passive transport
diffusion, osmosis, facilitated diffusion
types of active transport
endocytosis, exocytosis, protein pumps, contractile vacuole
active transport
transport that requires ATP (energy)
sodium-potassium pump
A special transport protein in the plasma membrane that transports sodium out of the cell and potassium into the cell against their concentration gradients.
Endocytosis
when a cell engulfs a large molecule or even an entire cell and a portion of the PM will wrap around the molecule forming a vesicle
what are the two types of endocytosis?
phagocytosis and pinocytosis
Phagocytosis
the cell taking in solid material; cell eating
Pinocytosis
the cell taking in liquid material; cell drinking
Exocytosis
cell expelling materials such as waste, indigestible particles, and hormones
contractile vacuole
an organelle in freshwater protists that remove remove excess water from the cell
cell
smallest unit of life
what is the cell theory?
All living things are made up of cells, cells are the basic unit of living things, new cells are produced from existing cells
Unicellular
A single celled organism
Multicellular
made of many cells
Examples of unicellular organisms
bacteria, amoeba, paramecium
prokaryotic cell
type of cell bacteria are made of that have no nucleus and has a cell wall
Archeabacteria
ancient bacteria; live in extreme conditions
Eubacteria
all other bacteria fall into this category
Eukaryotic cells
Contain a nucleus and other organelles that are bound by membranes.
Plasma (cell) membrane
a flexible boundary of a cell that is made up a phospholipid bilayer; in all cells
selectively permeable
controls what passes in or out
Cytoplasm
A jellylike fluid inside the cell in which the organelles reside; in every cell
ribosomes
where proteins are made; in every cell
where can you find ribosomes?
Rough ER and cytoplasm
What must all cells have?
Cytoplasm, cell membrane, genetic material, ribosomes, cytoskeleton
Nucelus
Control center of the cell that holds DNA; in all eukaryotic cells
DNA
directions to make proteins; in all cells
Chromosomes
condensed DNA
chromation
uncondensed DNA
Nucleolus
dense area inside nucleus that produces ribosomes; in all eukaryotes
Endoplasmic Reticulum (ER)
tubes and channels that transport materials throughout the cell; in all eukaryotes
smooth ER
ER that has no ribosomes
rough ER
ER that is dotted with ribosomes
Golgi apparatus
after proteins and lipids arrive in vesicles they go here to be packaged and shipped; in all eukaryotic cells
vesicle
sacs that move through the cytoplasm in and out of the cell; in all eukaryotes
Lysosomes
sacs filled with powerful digestive enzymes that digest things like worn out cell parts; only in animal cells
central vacuole
used for storage of water, minerals, and salts in a plant cell; only in plant cells
Mitochondria
produces ATP for the cell by breaking down glucose (cellular respiration); in all eukaryotic cells
Chloroplast
does photosynthesis and creates the pigment chlorophyll which makes plants green; only in plant cell
cell wall
strong, supporting layer around the cell membrane; in plant, fungi, bacteria, and some protist cells
Cytoskeleton
gives the cell shape, organization, and structure; present in all cells
What is the cytoskeleton made of?
microtubules, microfilaments, intermediate fibers
Centrioles
helps separate chromosomes during mitosis; only in animal cells
Flagella
whiplike tails structure for movement; only found in some types of cells but can be found in both prokaryote and eukaryote
cilia
short hair-like extensions for movement and sometimes feeding; only found in some types of cells but can be found in both prokaryote and eukaryote
What makes eukaryotes different from prokaryotes?
has a nucleus and more organelles
What makes prokaryotes different from eukaryotes?
they have no nucleus and they are less complex
what makes an animal cell different from a plant cell?
has lysosomes, centrioles, more circular in shape, and has no cell wall, chloroplasts, or central vacuole
what makes a plant cell different from an animal cell?
has a cell wall, chloroplast, and central vacuole, more rectangular in shape
Robert Hooke
looked at a cork through a microscope and found cells and named them cells
Anton van Leeuwenhoek
made first simple microscope and looked at pond water through it and saw the first living cells
Robert Brown
discovered the nucleus
M.J. Schleiden
said plants are made of cells
Theodor Schwann
said all animals are made of cells
Rudolf Virchow
proposed that new cells are formed only from cells that already exist ("every cell from a cell")
endosymbiotic theory
eukaryotic life began when a prokaryotic cell took up residence inside another prokaryotic cell and evolved into mitochondria and chloroplasts
what evidence do we have to support the endosymbiotic theory?
both have their own DNA and ribosomes that resembles eukaryotic structure, same size and shape, have two membranes inner membrane was their own membrane and the outer was the membrane of the cell they resided in
what are the levels of multicellular organisms?
cell, tissue, organs, organ system, organism
what are the five kingdoms?
Monera, Protists, Plants, Fungi, Animals
functions of proteins
build strong structures, transport things things throughout the body, speed up chemical reaction
elements in proteins
C, H, O, N, S
what is the monomer of proteins?
amino acids
how many types of amino acids are there?
20 types
what are the three parts of amino acids?
amino group (NH2), carboxyl group (COOH), "R" group
What are the polymers of proteins?
proteins; polypeptides
what are the bonds between amino acids called?
peptide bonds
enzymes
speed up chemical reactions by lowering activation energy
substrate
the molecule entering a reaction
activation energy
Energy needed to get a reaction started
lock and key
each enzyme is specially designed for one type of substrate
denature
to lose its shape irreversibly
primary structure of protein (1°)
sequence of amino acids
secondary structure of protein (2°)
hydrogen bonds form between different amino acids cause strain to form helix or pleated sheet shape
tertiary structure of protein (3°)
R-groups interact causing folding (last stage for some proteins)
quaternary structure
2 or more amino acid chains join together (not all proteins reach this stage)
active site
a region on an enzyme that binds to a protein or other substance during a reaction.
what is the function of nucleic acids?
store genetic code that tells cells how to make proteins in the form of a code
what are the elements in nucleic acids?
C, H, O, N, P
what are the monomers of nucleic acids called?
nucleotides
what are the three parts of a nucleotide?
a nitrogen base, a sugar, and a phosphate group
what are the letters of the nitrogen base for DNA?
G,A,C,T
what are the letters of the nitrogen base for RNA?
G,A,C,U
what are the polymers for nucleic acids
DNA and RNA
Note
Flashcard