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Terms in this set (16)

*Effect on gas exchange
-Increased evaporation
-More rapid uptake of ions by plants
-Decreased affinity for oxygen of haemoglobin

*Effect on proteins
-Increased rate of enzyme activity
-10 degree C rise= increase enzyme action by 75%
-Increased effect on growth and activity
-Increased rate photosynthesis with small increases in temperature
-Discruption of photosynthesis with large increases in temperature
-Increased rate of denaturing of tertiary structure

*Effect on transpiration
-Increased rate of water loss- wilting/dehydration
-Reduced stomatal opening may affect photosynthesis- consequences of drought
-Increased capacity of air to absorb more water
-Increase in air temp warms water inside leaves quickly causing faster evaporation
-Evaporation and diffusion are faster

*Effect on food webs
-changes to niches and communities
-Earlier springs= earlier nesting for 28 migratory bird species on E. coast of US
-16/23 butterfly species in California shifted migration timing
-Decline in sea ice= less algae= less zoo plankton= less cod= less seals= less polar bears
-Irreversible changes when threshold is passed
-World's oceans reached 17 degrees C= highest ever

*Effect on growth and reproduction
-Spread of pathogens, parasites, diseases
-Effect on human health
-Weeds, pests, fungi compete with crops for light, water, nutrients

*Effect on agriculture
-Higher temperatures= more rain
-Higher temperatures= more drought
-Impacts on crop yields (some increase/some decrease)
-Farmers move crop locations
-Threatens livestock- reduce fertility, increase disease, reduce milk production, reduce forage
*Action Potentials
-In resting potential, concentration of sodium ions outside membrane is high, potassium is low. Sodium pumped out, potassium pumped in to produce electro-chemical gradient
-High stimulus produces positive charge of +40mV, causing channels to change shape and sodium ions move into axon
-Once +40mV is reached, sodium ions close, potassium ions open
-Overshoot of gradient when more potassium pumped out (repolarisation)

*Nitrogen Cycle
-Plants take up nitrogen as nitrate ions- absorbed by active transport
-Nitrate ions leach through soil
-Nitrogen fixation (gas into compounds)
-Ammonification (ammonia into ammonium ions)
-Nitrification (ammonium ions into nitrite ions, nitrite ions into nitrate ions)
-Denitrification (nitrates into gas)

*Fertilisers and plant growth
-Artificial fertilisers contain nitrogen, phosphorous, potassium
-Nitrogen essential in amino acids, ATP, DNA nucleotides
-Where nitrate ions are available, plants develop earlier, grow taller, greater leaf area, more photosynthesis
-Cheaper food due to increased productivity

*Role of H+ in respiration
-Oxidation of TP (removal of H+)
-Production of NADH, FADH

*Role of H+ in photosynthesis
-Photolysis splits water into H+ ions and OH+ ions
-Chemiosmotic theory (H+ pumped from stroma into thylakoid membrane, ATP formed)
-GP/TP formation in light independent reaction
-Produces starch, cellulose, lipids etc.

*Hydrogen, pH and Enzymes
-pH= hydrogen ion concentration
-pH= -log10(H+)
-Extreme change= denaturation
-Alters charges on amino acids tat make up active site of enzyme
-Tertiary structure may change so substrate no longer binds to active site of enzyme
-pH fluctuations usually small- more likely to reduce activity than denature it.
*Muscle Contraction
-Head of mysosin changes angle, moves actin along and releases ADP
-ATP fixes to myosin head, causing it to detach from actin
-Hydrolysis of ATP to ADP by ATPase provides energy for myosin head to resume normal position
-During muscle relaxation, ATP provides energy for calcium ions to be actively transported back to ER

*Respiration
-Glycolysis- Phosphorylation of glucose to GP using ATP, Oxidation of TP to pyruvate, producing ATP
-Krebs Cycle- ATP produced in o-r reactions
-Oxidative Phos- synthesis of ATP down transfer chain, catalysed by ATP synthase

*Photosynthesis
-Energy/ATP produced through electron transfer chain
-Protons through chloroplast membranes catalysed by ATP synthase embedded in membranes
-Hydrolysis of ATP from light-dep reaction provides energy for light-indep reaction
-ATP and NADPH used to reduce GP to TP

*Blood Glucose concentration- 2nd Messenger Model
-Raises glucose levels when too low
1. Adrenaline approaches transmembrane protein
2. Adrenaline fuses to receptor causing it to change shape, activating adenyl cyclase
3. Activated adenyl cyclase converts ATP to cAMP
4. cAMP activates protein kinase
5. Active protein kinase converts glycogen to glucose

*Active Transport of Ions
-Sodium ions into descending limb, out of ascending limb in nephron to control water
-Sodium ions into, potassium ions out of axon in action potential
-Sodium ions out of, potassium ions into resting potential
-AP travels through tubules, tubules in contact with sarcoplasmic reticulum which has actively transported calcium ions from cytoplasm of muscle

*Protein Synthesis
-5 ATP molecules required for addition of a single amino acid to a polypeptide chain
-2x ATP for amino acid activation, 2x ATP for peptide bond, 1x ATP for error correction
*DNA
-DNA codes for proteins
-Proteins responsible for expressing information in DNA
-DNA wrapped around proteins called histones- DNA and histones covered in tags to form epigenome which determines shape of DNA-histone complex- controls which genes are switched on/off using methylation and acetylation

*Haemoglobin
• Globular protein with a quarternary structure
• Largest component of red blood cells
• Loads, transports and unloads oxygen
• Oxygen binding to first site makes other bindings easier
• Its evolution and small mutations in its structure can produce anaemia and other severe pathologies

*Immunology
• Antibodies are blood proteins produced in response to and counteracting a specific antigen.
• Complementary primary structure enables binding
• Lysozymes involved in phagocytosis to ingest pathogen
• Lymphocytes produce antibodies.
• Vaccines contain small quantities of weakened antigen- antibodies and memory cells produced

*Across Membranes
• Embedded proteins in membranes
• Act as antigens to allow them to be recognised
• Glycoproteins in fluid-mosaic model allow communication between cells
• Carrier proteins in Facilitated diffusion- Once a specific molecule collides with the Carrier Protein, it 'flip flops' carrying the molecule to the other side of the membrane. The Carrier Proteins involved in Active Transport are Complementary to the molecule they transport.
• Channel proteins in facilitated diffusion provide pores though which these molecules can diffuse

*Enzymes in Respiration
• acetate combines with coenzyme A in the link reaction to produce acetyl coenzyme A
• acetylcoenzyme A reacts with a four-carbon molecule, releasing coenzyme A and producing a six-carbon molecule that enters the Krebs cycle
• Synthesis of ATP by passage of protons across inner mitochondrial membranes and is catalysed by ATP synthase embedded in these membranes (chemiosomotic theory)

*Enzymes in Photosynthesis
• passage of protons across chloroplast membranes and is catalysed by ATP synthase embedded in these membranes(chemiosomotic theory)
• carbon dioxide reacts with ribulose bisphosphate (RuBP) to form two molecules of glycerate 3-phosphate (GP). This reaction is catalysed by the enzyme rubisco