cell structures & functions Flashcards
what are the smallest units of life
cells
what are the 4 features both prokaryotes & eukaryotes have
DNA, plasma membrane, cytoplasm, ribosomes
prokaryotes
no nucleus, or membrane-bound organelles, unicellular, simple
eukaryotes
has nucleus, membrane-bound organelles, multicellular) but some uni), complex
photosynthesis
occurs in plant cells, takes place in chloroplast
photosynthesis reactants & products
water + carbon dioxide + sunlight = glucose & oxygen
cellular respiration
occurs in plant & animal cells, takes place in mitochondria
cellular respiration reactants & products
glucose + oxygen = water, carbon dioxide & ATP
active transport
sodium/potassium pump, endocytosis, exocytosis
active transport definition
moves molecules in & out of the cell using a protein pump in the cell membrane (USES ENERGY)
endocytosis definition
cell membrane eats/ingests foods or liquids into the cell
exocytosis definition
a cell releases a substance like hormones or wastes through the cell membrane
Passive transport
does not require energy - diffusion, facilitated diffusion, osmosis
diffusion meaning
movement of small molecules from area of high to low concentration
facilitated diffusion meaning
uses protein channels to move larger molecules that cannot pass thru the cell membrane, does not need energy
osmosis meaning
movement of WATER ONLY across cell membranes of cells (does not need energy)
what energy molecule do cells use
ATP [adenosine triphosphate - contains 3 phosphates]
what bond stores the most energy in ATP
the bond between the 2nd & 3rd phosphate
what molecule is formed when a phosphate is released from ATP
ADP [adenosine diphosphate - has 2 phosphates]
when the cell has energy available from food, what can happen?
When the cell has energy available from food, it can store energy in the bond by adding a third phosphate to ADP to create ATP
does ATP or ADP have the most energy?
ATP
in bacteria cells, where does cellular respiration take place
cytoplasm
2 steps of cellular respiration
glycosis & krebs cycle
does glycosis require oxygen
no
if oxygen is present, what is the next step after glycosis
cellular respiration (aerobic respiration)
if oxygen is not present, what is the next step after glycosis
fermentation (anaerobic respiration)
what is the difference between cellular respiration & fermentation in regards to production of ATP
cellular respiration makes 36 ATP & fermentation makes 2 ATP
2 types of fermentation
Lactic acid (happens in muscles) & alcoholic (bacteria & yeast) fermentation
disadvantage of fermentation
net ATP is much lower when you don’t have oxygen available
cell theory
all living things are composed of cells, the cell is the basic unit of life, cells arise from pre-existing cells
modern cell theory
energy flow occurs within cells, DNA is passed on from cell to cell, all cells have the same basic chemical composition
endosymbiotic theory
the explanation for the orgin of eukaryotic cells
nucleus
contains DNA, controls cells’s growth & reproduction, found in animal & plant
mitochondria
converts energy into usable forms thru cellular respiration, found in animals & plants
cell membrane
semi-permeable, protects interior of cell, found in animals & plants
cell wall
provides support & protection, found in plants only
chloroplast
contains chlorophyll, converts radiant energy into chemical energy via photosynthesis, found only in plants
endoplasmic reticulum
manufactures membranes, proteins, carbs, lipids, hormones & transports to other organelles, found in both animals & plants
golgi complex
manufactures, stores & ships cellular products, found in both animal & plant cells
vacuole
stores water, nutrietns, and waste, found in both plants & animals, but larger in plants
lysosomes
sacs of enzymes that digest macromolecules, found in both
ribosomes
site of protein synthesis, found in both
cytoplasm
cytosol & all contents of the cell except the nucleus, cell process occurs here, found in both
hypertonic
higher solute concentration [turgid]
hypotonic
water comes in, and fills up the cell & about to burst
isotonic
equilibrium, cells are happy
