4-5.9 test notes Flashcards
high surface area to volume ratio makes
efficient cells
to calculate surface area of a cube you
Length x Width x 6 mm ^2 (squared)
to calculate volume of a cube
Length x Width x Height mm ^3 (cubed)
Cells with odd shapes
have greater surface area to volume ratio
semi/selectively permeable, plasma membrane all mean?
cell membrane
The cell membrane helps
communicate with other cells, creates attachments between cells and protects the cell
is used for transport and maintaining homeostasis
thin, liquid bilayer , that is semi-permeable, regulates movement on materials, entering and exiting the cell
Exocytosis
move stuff out —> vesicle fuses with membrane
typically the secretion of larger molecules
Endocytosis
bring in —> take in macromolecules by forming vesicle around it
Phospholipid bilayer
allows flexibility, prevents water from flooding, allows small non polar molecules through easily (ex. oxygen and co2)
Pinocytosis
cell drinking fluid
non-specific
Phagocytosis
cell eats
targets large structures + not particularly specific
Passive transport
Requires no energy
Movement from a high concentration to a low concentration
Diffusion
particles moving from a high to low concentration
ex. air freshener and perfume 
diffusion across the membrane is too slow
equilibrium
particle/molecules are equal on both sides of the membrane
osmosis 
movement of water from HC to LC across the cell membrane 
isotonic 
equal, both moving in and out 
hypertonic 
solution is greater on the outside water moves out (shrinks)
hypotonic 
solution is greater inside water moves in (bursts) 
turgor pressure 
cell wall sustains shape, otherwise would explode 
Aqua Porins 
Channel proteins, that help transport water across the membrane —> necessary bc water is polar! 
Active transport 
moving from LC to HC —> requires energy 
sodium potassium pump helps
keep ions in place, making a concentration gradient low —> high
Cell theory (3)
- all living things are composed of cells
- cells are the basic unit of structure and function for living things
- All cells come from pre-existing cells 
how do organisms grow
by adding on more cells NOT by increasing the size of their cells
minimum cell size

A cell must be large enough to house, enough, DNA, protein, molecules, and structures to survive and reproduce 
maximum cell size 
a cells size is influenced by geometry, the need to have a surface area large enough to service the volume of a cell

Plasma membrane
has both lipids and proteins
forms stable barrier between two aqueous compartments
provides protection for a cell and a fixed environment inside the cell 
transports nutrients in and toxic substances out
The fundamental structure of the membrane is 
The phospholipid bilayer 
structure of prokaryotic cells 
always unicellular, smaller, and simple 
eukaryotic cell structure 
are often multicellular, additional me or 100 to 10,000 times larger and more complex 
compartmentalization increases 
The efficiency of many sub cellular processes by concentrating the required components to a confined space within the cell 
animal cells 
have one or more small vacuoles, and will change according to what solution they’re under 
plant cells 
have one large central vacuole that can take up to 90% of cells volume and will change according to what solution they’re under 
outcomes of organelles malfunctioning 
diabetes, heart disease, Alzheimer’s, disease, Parkinson’s disease, and even normal aging 
structure and function of the nucleus 
Controls and regulates the activities of the cell (ex. grow the metabolism) and carries genes, structures that contain hereditary information 
structure and function of the nucleolus 
facilitating ribosome biogenesis through the process and assembly of RNA into Peribosmal particles 
 Ribosome functions
decoding a message and the information of peptide bonds, they link together specific amino acids to form polypeptides. Then they export these into the cytoplasm. 
Endo membrane system 
produces all the transmembrane proteins and lipids for most cell organelles 
function and location of the mitochondria 
found in plant and animal cells and generates energy for the cell in the form of ATP using oxygen and nutrients 
microfilaments
thicken the cortex around the inner layer of cell, they resist tension 
Microtubules
found in the interior of the cell. They maintain cell shape by resisting compressive forces. 
intermediate filaments 
found throughout the cell and hold organelles in place 
phospholipid molecules 
The phosphate head is hydrophilic, (water-loving)
The fatty acid tails are hydrophobic (water-hating) 
transport proteins do what

facilitate diffusion by proteins binding the molecule the molecule being transported on the surface of the membrane, then passes it to the interior proteins that typically form a channel or pore in the membrane 
Chloroplast location
found in plant cells and is the site of photosynthesis in a plant cell
