essay no title Flashcards
(11 cards)
Muscles links to
ventilation
ventilation A02 link paragraph
1- inhalation- the external intercostal muscles contract and the internal intercostal muscles relax.
2- allows volume to increase in the thoracic cavity
3- pressure to decreases
4- causing air to move in through the trachea and down the bronchi, into the bronchioles and finally reach the alveoli.
5- This mechanism is important for effective gas exchange allowing oxygen to enter the bloodstream and carbon dioxide to be expelle
Muscles paragraph A01
AO1:
1- Action potential arrives at neuromuscular junction - causes Acetylcholine (ACh) to be released into neuromuscular junction.
2- ACh binds to specific receptors on the sarcolemma- causing depolarisation - spreads via T- tubules, release of calcium ion from sarcoplasmic reticulum into the sarcoplasm.
3- The calcium ions bind, to specific sites on the muscle filaments causing a change in shape of tropomyosin, which exposes the binding sites on the actin filaments.
4- Myosin heads with ADP attached then bind to these exposed sites, forming myosin-actin crossbridge.
5- The myosin heads undergo a power stroke, pulling the actin filaments along, powered by the energy released from ATP hydrolysis catalysed by ATP hydrolase.
6- An ATP molecule binds to each myosin head, causing them to detach from the actin, allowing the cycle to repeat as the myosin heads reattach further along the filament.
7- This process allows for the contraction of muscle fibres upon a stimulation. This is important for organism in the process of Ventilation.
Protein synthesis links to
specific protein - antibodies
antibodies AO2 link
1- proteins - with variable regions
2- that bind specifically to antigens on pathogens.
3- this specific binding neutralizes pathogens and marks them for destruction by immune cells, such as phagocytes.
4- The importance of antibodies lies in their role in adaptive immunity, providing targeted defence against infections and contributing to long-term immunity through memory cells.
protein synthesis AO1
1- Transcription, DNA helicase unwinds the double helix by breaking hydrogen bonds between complementary base pairs.
2- Hydrogen bonds allow for free RNA nucleotides via complementary bonding pairs, to align and RNA polymerase to joins the adjacent nucleotides forming phosphodiester bonds between RNA nucleotides, in a condensation reaction (removing water).
3- These bonds also create the sugar-phosphate backbone, providing structural stability and enabling the transfer of genetic information.
4- Bonds are important for allowing for translation to occur, creating a polypeptide chain.
5- Translation mRNA attaches to ribosomes, where MRNA codons are read and tRNA anticodons bind to complementary mRNA codons, bringing specific amino acids.
6- Ribosomes enables condensation reactions to form peptide bonds form between the carboxyl group of one amino acid and the amine group of another amino acid, creating a polypeptide chain with a specific tertiary structure…
Cotransport links to
respiration or specific protein
contrasport A01
1- This is the movement of substances across the cell membrane via carrier protein.
2- Cotransporter protein can be found at the cell surface membrane of the epithelium cells lining the ileum.
3- Sodium ions move into the cell from the ileum by facilitated diffusion, carrying amino acid molecules along with them via the cotransporter protein.
4- Sodium is then transported out by active transport and the sodium potassium pump via the carrier protein using ATP into the blood.
5- This lowers the sodium ion concentration inside the cell and creates a sodium ion concentration gradient between the ileum and the epithelial cell.
6- The amino acid concentration inside the epithelial cell increases and amino acids enter the blood via facilitated diffusion
respiration link
- aerobic respiration, glycolysis, to occur.
1- Glucose is phosphorylated in to glucose phosphate in the cytoplasm by the hydrolysis of two ATP molecules to ADP and Pi.
2- This provides energy to allow glucose to be split to triose phosphate.
3- This is then oxidised (hydrogen is removed), reducing NAD to NADH.
4- Finally, triose phosphate is converted into pyruvate, which regenerates two molecules of ATP from ADP per molecule of pyruvate.
Photosynthesis AO1 para
light-dependent reaction
1- the absorption of light energy by chlorophyll pigments embedded in the thylakoid membrane.
2- This absorption leads to the excitation of electrons in the chlorophyll molecules, a process known as photoionization.
3- The excited electrons are then transferred through a series of electron carriers in the electron transport chain
4-. As they move through this chain, they release energy that is used to actively pump H+ ions, derived from the photolysis of water, across the thylakoid membrane, thus creating an electrochemical gradient.
5- Photolysis of water not only provides these protons but also releases oxygen as a by product.
6- The H+ ions then diffuse back into the stroma via ATP synthase, driving the synthesis of ATP from ADP and inorganic phosphate.
7- Simultaneously, the electrons reduce NADP to form reduced NADP, which is essential for the light-independent reactions in the Calvin cycle.
photosynthesis AO2 para
light independent stage
1- Carbon dioxide reacts with ribulose bisphosphate and forms two molecules of glycerate 3-phosphate catalysed by the enzyme rubisco and then GP is reduced to triose phosphate by energy from ATP and by accepting a H from reduced NADP.
2- It results in some of the carbon from TP leaves the cycle each turn to be converted into useful organic substances.
