Chapter 3 - Biochemical Processes in Cells Flashcards
cellular metabolism
the sum total of chemical reactions that occur in each living cell
anabolic reactions / endergonic
chemical reaction in which atoms and molecules are joined together to make more complex molecules
energy required
e.g. photosynthesis
catabolic reactions / exergonic
reactions that break down complex molecules into simpler molecules
release energy
e.g. cellular respiration, digestion
ATP
adenosine triphosphate
contains adenosine and 3 phosphate
renewable energy source
ADP
adenosine diphosphate
contains adenosine and 2 phosphate
phosphorylation
the addition of a phosphate group to an organic molecule
ADP + Pi = ATP
enzyme
proteins which are capable of catalysing (speeding up) biochemical reactions by reducing the activation energy
biological catalysts
specific: catalyse only one type of reaction
recyclable: remains unchanged, used again
active site
the region of the enzyme to which the substrate binds
substrate
compound on which an enzyme acts
enzyme substrate complex
combination of the enzyme and its substrate
lock and key model
substrate fits into the active site perfectly
rigid active site
highly specific
Induced fit model
active site changes shape slightly to fit the substrate
flexible
increases range of substrate specificity
activation energy
the amount of energy needed to start a chemical reaction
enzymes lower activation energy
factors affecting enzyme activity
pH
temperature
enzyme and substrate concentrations
inhibition
factors affecting enzyme activity
pH
enzyme denatured in extreme pH
buffered solutions
factors affecting enzyme activity
temperature
enzymes work best in temp they’re found in
temp increases: molecules more excited and collide more often
denaturing
temp too low: little to no activity
denaturing
hydrogen bond broken by heat
protein loses 3D shape: active site changed
irreversible
factors affecting enzyme activity
enzyme and substrate concentrations
increases substrate: more product until enzyme worked to full capacity
increased enzyme: increases yield of the production until substrate all used up
factors affecting enzyme activity
inhibition
chemical substances that interfere with enzyme function
inhibitors
compete with the substrate for the active site
competitive and non-competitive
competitive inhibitors
can fill the active site of the enzyme preventing it from binding with the substrate
non-competitive inhibitors
can attach to the enzyme causing a change in the shape of the active site
rational drug design
construction of a drug to fit the active site of a molecule so that the natural action of the molecule cannot occur
rational drug design steps
- research and identify the metabolic pathway of the pathogen
- identify structure of enzyme: tertiary and active site
- design and create a drug with the same shape as active site to act an inhibitor
- active site blocked: cannot bind with pathogenic substrate;; prevents disease
cofactors
metallic cation that binds to the enzyme and increases the rate of catalysis
essentail for normal enzyme function
coenzymes
assist in the catalysis by binding to enzymes or by functioning as carriers of electrons and protons
acts with an enzyme to alter the rate of a reaction
photosynthesis
the process in which green plants trap light energy in their chlorophyll and use carbon dioxide and water to create chemical energy as carbohydrates
plants make own food
overall equation photosynthesis
carbon dioxide + water (light) -> glucose + oxygen
6CO2 + 6H2O -> C6H12O6 + 6O2
chloroplast
chlorophyll containing orangeade that occurs in the cytosol of cells of specific plant tissues
chloroplast structure
stroma: gel like matrix
thylakoid: flat sac-structures - grana when stacked
light dependent reaction
involves trapping light energy by chlorophyll and its conversion into chemical energy
occurs in grana
steps of light dependent reaction
light energy trapped by chlorophyll
energy used to produce ATP and to split water molecules to form hydrogen ions and the waste product oxygen
H+ ions gathered by NADP -> NADPH
light independent reaction
involves the formation of sugar molecules from carbon dioxide
occurs in stroma
not dependent on light, dependent of the light dependent stage
steps of light independent reaction
input of carbon dioxide, H+ ions and ATP carbon atoms removed from carbon dioxide C atoms combine with H+ from NADPH energy supplied by ATP glucose produced
location of light dependent reaction
grana
location of light independent reaction
stroma
inputs of light dependent reaction
water
light energy
NADP+
ADP + Pi
outputs of light dependent reaction
NADPH
ATP
oxygen
hydrogen
inputs of light independent reaction
NADPH
ATP
CO2
outputs of light independent reaction
glucose
NADP+
ADP + Pi
factors affecting photosynthetic rate
intensity of light
carbon dioxide concentration
temperature
abundance of chlorophyll
cellular respiration
the series of energy releasing reactions that break down organic compounds, releasing chemical energy and transferring it to ATP
is cellular respiration anabolic or catabolic
catabolic
mitochondria structures
inner membrane: cristae and matrix
outer membrane
aerobic respiration
breakdown of glucose to simple in organic compounds in the presence of oxygen and with release of energy that is transferred to ATP
steps of aerobic respiration
glycolysis
Kreb’s cycle
Electron transport
aerobic respiration - glycolysis
occurs in cytosol
one molecule of glucose (6C) broken down into two molecules of pyruvate (3C)
two ATP molecules are produced per glucose molecule
aerobic respiration - Kreb’s Cycle
occurs in matrix
pyruvate from glycolysis passes through cytosol and broken down into CO2 and H2O
H atoms gathered by acceptor molecules
4 NADH and 1 FADH2 produced (5 loaded acceptors)
aerobic respiration - electron transport
occurs in cristae
loaded acceptors from Kreb’s move to cristae
electrons are transferred between cytochrome’s (compounds in cristae) until accepted by oxygen
becomes negatively charged and reacts with H+ ions to form water
releases energy
overall equation of cellular respiration
glucose + oxygen -> water + carbon dioxide + energy
C6H12O6 + 6O2 -> 6H2O + 6CO2 + ATP
anaerobic respiration
form of respiration that occurs in the absence of oxygen in which glucose is broken down into smaller compounds, with release of energy that is transferred to ATP
occurs in cytosol
rapid but less efficient
anaerobic respiration - animals equation
glucose -> lactic acid + 2ATP
anaerobic respiration - plants equation
glucose -> ethanol + carbon dioxide + 2 ATP
Fermentation
Process of anaerobic respiration in yeasts that results in alcohol formation
Autotrophic
Organism that can produce its own food from simple inorganic substances
Glycerol
three fatty acids linked to form a lipid
Pyruvate
3C compound
Formed in first stage of cellular respiration
