ATP, Water and Reactions Flashcards
Endocytosis
a cell surounds a substance with a section of its cell membrane,
the membrane pinches off to form a vescile inside the cell,
What uses Endocytosis
Phagocytes use endocytosis to ingest and digest bacteria and dead cells
What is taken in through Endocytosis
Cholesterol
Exocytosis
vescile containing substances fuses with the membrane and releases the substances outside the cell
What is removed by Exocytosis
enzymes and antibodies
Exergonic reaction
relases energy
Endergonic reaction
needs energy to drive them
Exothermic reaction
releases heat
Endothermic reaction
takes in heat
Respiratation / Combustion of Glucose
glucose + oxygen —-> carbon dioxide +water+ energy,
ATP
Adenosine Triphosphate:
Adenine, Ribose, 3 Phosphate Groups.
ATP Hydrolysis
ATP + H2O ——> ADP + Pi
gives out energy
Break down of ATP
ATP can be broken down into ADP + Pi which are used to re-synthesised more ATP.
Breaking bonds to release energy happens in a single step reaction so energy is released quickly.
Negatively Charged Phosphates are…….
under stress due to charges repelling,
this releases energy as the bonds are broken.
Substrate Level Phosphorylation
High energy PO4^2- transferred from other molecules to ADP.
Oxidative Phosphorylation
The energy of oxidation reactions provides the energy to phosphorylate ADP.
Photophosphorylation
Thylakoid membranes in plants use light energy to add a phosphate group to ADP.
ATPase
An enzyme which hydrolyses
ATP ——–> ADP + Pi
ATP synthase
An enzyme which synthesises ATP from ADP + Pi
Transmembrane ATPase
A protein which spans the membrane and hydrogen ATP.
Anabolic Reactions
Build macromolecules from smaller ones,
Require energy input (ATP hydrolysis),
e.g. protein synthesis and formation of polysaccharides.
Catabolic Reactions
Break down of large molecules into smaller ones,
releases energy,
e.g. hydrolysis of starch
Energy uses in:
Anabolic Reactions
Synthesis of protein and DNA.
Energy uses in:
Haeting the Organism
Waste energy from transfer.
Energy uses in:
Active Transport
Secretory activities (endocytosis/exocytosis).
Energy uses in:
Muscle Contraction
To pump more blood around the body.
Energy uses in:
Cell Division
mitosis,
meiosis,
binary fission.
Energy uses in:
ATP Hydrolysis
Glucose would relase too much energy to be channelled into cellular reactions when hydrolysed,
in efficient use of this energetic molecule,
ATP releases nice ‘packets’ of energy that are just enough for one cjemical reaction,
the reaction happens all in one step and not several.
Water
polar solvent molecucle,
it is not charged overall,
the oxygen atom has a slight negative charge and the hydrogen atoms have a slight postivie charge,
water is dipolar.
Binding of 2 water molecules
water molecules are attracted to each other,
held together by hydrogen bonds.
Hydrogen Bonds
weaker than covalent bonds but together in numbers are strong.
The Universal Solvent
so much can dissolve in water however it is not truly universal.
High `specific Heat Capacity
It takes alot of energy to change the temperature of water due to the hydrogen bonding between molecules,
temperature changes are small in aquatic ecosystems and in organisms (which are mainly water).
Latent Heat of Vaporistaion
It takes a lot of energy to make water evaporate,
when sweat evaporates energy from the surface of the organism is removed,
the cools the body.
Cohesion and Surface Tension
water molecules stick together,
they form long columns when they are drawn up plants,
tehy form a surface that pond skaters can live on in bodies of water.
Density of the Solid Upon Freezing
Ice is less dense than water,
it forms an insulating layer on the surface of a pond when it freezes from the top down protecting aquatic organisms.
water reisits change of state because….
hydrogen bonding,
this moderates earths temperatures.
water resists changes in temberature because…..
hydrogen bonding helps keep our body temperature constant
water is a universal solvent because….
its polarity which facilitates chemical reactions.
water is cohesive and adhesive because……
hydrgen bonding and polarity,
it serves as a transport medium.
water has a high surface tension because…….
hydrogen bonding menas it is difficult to break surface tension.
water is less dense as ice than liquid water because…..
hydrogen bonding,
resulting in ice floating on water.
water catalyses…….
photosynthesis,
condesation reactions,
hydrolysis reactions.
water is not……
easily compressible which forms the hydrostatic skeleton in worms.
water is transported so……
plants can live underwater
All ions dissolve in water
All ions dissolve in water
ATP Synthesis
ADP + Pi ——-> ATP
Energy input
