T1 M2 Organelles, Energy and App lec Flashcards
oxidative phosphorylation
using oxygen as the final electron carrier in the ETC, resulting in the production of water
substrate-level phosphorylation
synthesis of ATP by adding a phosphate group to an ADP molecule
endomembrane system
- present in eukaryotic cells
- incl the nuclear envelope, and other membrane structures such as the ER, golgi apparatus and plasma membrane surrounding the cytoplasm
- perform most lipid and protein synthesis
- allows for phagocytosis and exocytosis which involve compartmentalization of things entering and exiting the cell
are chloroplasts and mitochondria included in the endomembrane system?
no because they are likely bacteria that were engulfed by eukaryotes over time and evolved to develop their present function
- also they have their own DNA
prokaryotic cells
unicellular organisms lacking a nucleus and have few to no organelles
eukaryotic cells
organisms whose cells contain a nucleus and many membrane bound organelles
photosynthesis
process used in plant cells to convert light energy into chemical energy that will get stored in the bonds of carbohydrate molecules
- happens in double membraned chloroplast
cellular respiration
process used in plant and animal cells to release energy stored in bonds of carb molecules and form ATP
- happens in double membraned mitochondria
about how many mitochondria are there in a cell?
anywhere from 50 to 1,000,000
how are mitochondria similar to bacteria
- they have their own circular genome
- produce enzymes necessary for protein synthesis
- about same size and appearance as bacterial cells
endosymbiotic theory of organelle evolution
states that early eukaryotes became hosts to aerobic and photosynthetic prokaryotes which we now know as mitochondria and chloroplasts
– these temporary relationships are permanent and heritable thus they are part of the cell now
why are organelles important?
- they allow for compartmentalization. ie certain enzymes w like functions can be kept together
- also opposing functions can be kept separate
- increases membrane surface area
increased membrane surface area can cause what?
- increases potential metabolic capacity across the membrane
glycosidic linkages
covalent bonds formed b/w monosaccharides (condensation reactions) to form complex sugars
- give alpha or beta 1, 4 glycosidic linkages b/w OH groups on C1 and C4 molecules
name the monosaccharides
glucose
fructose
galactose
name the disaccharides
sucrose
lactose
maltose
polysaccharides
often storage from of energy
starch and glycogen
ETC
electron transport chain
- present in inner mitochondrial membrane
establishes a proton gradient used to produce ATP in mitochondria yields 36 ATP/ 32 idk hopefully this isn’t a question
how many ATP are yielded from a molecule of glucose
30
exergonic reaction
produces energy
ex. hydrolysis of ATP
ATP
composed of 3 phosphate groups, a ribose sugar and an adenine
- cleavage of a phosphate group yields 30.5 kJ/mol ATP
oxidation and reduction reaction
reduction: gaining e-
oxidation: losing e-
beta oxidation of FAs
allows fatty acids from lipids to be broken down into NADH and FADH2 and Acetyl CoA to yield energy
when sufficient carbohydrate is not present, the body will use what as energy?
lipids first, then proteins
glycerol -> glucose and enters cycle
AAs -> pyruvate -> TCA
the camel’s hump
- can weigh up to 80 lbs
- consists of pure fat (tristearin - lots of bonds can be broken to yield plenty of energy, also a source of water bc produces H2O when metabolized)
- size increases when replenishes food source and decreases when camel goes w/o eating for a long time
- camels have extreme water loss tolerance (30-40% is ok), long noses to keep moist air, dry feces
migrating geese
eat a lot in fall, to have enough energy to migrate, they can lose up to half of their entire body weight in fat
what is the most extreme bird
bar headed goose
- flies over mountains at high speeds – 65km/h
they break down FAs into bloodstream and proteins carry them to muscle cells where there are more mitochondria
- also have greater ventilation rates w thinner alveolar membranes at capillary beds w lots of mitochondria, Hb binds to O2 better
locusts
can fly over oceans
- start by breaking down glucose and after 30 mins begin using lipid stores as energy
ketone bodies
contain 38% more recoverable energy than glucose and FAs as they can be converted into acetyl coA
- are these an alternative source of fuel?
they are produced when more FAs circulate in the body
high ketone drink called delta G given to athletes can provided higher degree of energy.
is this doping? this is expensive. are there side effects?
some functions of proteins
- transport and signalling: hormones, protein channels
- movement and structure: myosin, actin
- enzymes
- defense: antibodies
nucleus
double membrane bound domain that contains chromosomes which pack and control DNA molecules, contains most of the genes in a eukaryotic cell
nucleolus
a non membrane bound spherical structure within the nucleus that contains the genes and transcripts for rRNA
nuclear pores
allow for things to move between nucleus and cytosol such as nucleic acids and enzymes
ribosomes
synthesize proteins
2 kinds produce diff kinds of proteins
- also remain free in cytoplasm or attached to ER until needed
condensation reactions that polymerize amino acids are where
catalyzed within the ribosome
chemical structure of a protein/ amino acid
central carbon w a H, amino group and carboxyl group
also a variable side chain connected to central C gives protein unique properties
peptide bonds
bonds b/w amino acids that are made via condensation reactions and result in formation of polypeptides
- form b/w OH group and amino group of 2 AAs
what is important about the properties of the side chain in a protein?
they dictate the shape of a protein
ie hydrophobic will slide inside and hydrophilic stays outside
primary protein structure
sequence of AA formation
secondary protein structure
folding into alpha helix or beta pleated sheet
alpha helix protein folding
polymer is turned into a spiral by formation of H bonds b/w carbonyl and carboxyl groups
- R groups stick out from helix
beta pleated sheet protein folding
broad lines w arrowheads made of parallel protein strands w H bonds also formed b/w carboxyl and amino groups of adjacent strands
- R groups extend above and below the B-sheet
- adjacent strands can run in opposite (antiparallel) or the same (parallel) direction
tertiary protein structure
3-D shape forms that will determine function
- determined by interactions b/w R groups
free ribosomes
translate proteins that will remain in the cytosol or be targeted to organelles that include the nucleus, mitochondria and chloroplasts
- some of these proteins incl enzymes for glycolysis, or structural proteins
what are some interactions b/w R groups that occur
H bonding, Van der Walls interactions, covalent and ionic bonding, disulphide bonding and hydrophobic interactions
quaternary protein structure
association of different polypeptide subunits to form a fully functional protein
molecular chaperones
proteins that bind to hydrophobic regions of nascent polypeptides and prevent incorrect folding long enough for the correct structure to form
chaperonins
large molecular complexes that form isolation chambers
- nascent proteins are held here so it doesn’t interfere with proper protein folding
