2024 Unit 1 Biology Extra Notes PDF
Document Details
Uploaded by ErrFreeArtDeco4706
St Bede's College
Tags
Summary
These notes provide an overview of cell organelles, material transport processes, such as simple diffusion, facilitated diffusion, and osmosis, and cellular respiration.
Full Transcript
Unit 1 Biology Extra Notes Cell Organelle Structures and Roles . N 1 ucleus-to protect and confine the genetic information(DNA) of the cell. 2. Ribosomes-either float freely in the cytoplasm orare attached to the rough ER. They are the site of assemb...
Unit 1 Biology Extra Notes Cell Organelle Structures and Roles . N 1 ucleus-to protect and confine the genetic information(DNA) of the cell. 2. Ribosomes-either float freely in the cytoplasm orare attached to the rough ER. They are the site of assembly of the building blocks to make proteins. 3. Chloroplast–s ite of photosynthesis where light iscaptured, glucose & oxygen are made 4. Rough Endoplasmic Reticulum–has ribosomes on surface,synthesises & modifies proteins 5. Smooth ER–s ite of synthesis of lipids 6. Golgi body-s ites of protein sorting, packaging,and modification for use in the cell or export out. 7. Mitochondria-s ite of aerobic cellular respirationreaction that produces the ATP. 8. Vacuole-water and solute storage, also maintainsplant cell structure Phospholipid bilayer Recognise and label structures: ydrophobic- repels water, (water hating), non polar H Hydrophilic- attracts water, (water loving), polar Material Transport Processes Simple Diffusion Where?Not just membranes Which direction?Down concentration gradient fromH to L - passive What substances can carry it out?Uncharged particless uch as lipid based s ubstances and gases – hydrophobic only Facilitated Diffusion Where?Protein carrier in membrane Which direction?Down concentration gradient fromH to L - passive What substances can carry it out?Large hydrophilics ubstances Osmosis Where?Phospholipids in membrane Which direction?Down concentration gradient fromH to L - passive What substances can carry it out?Water – hydrophilic Definition:The passive movement ofwateracross asemi-permeable membrane froman area oflow solute (high water) concentrationtoan area ofhigh solute (low water) concentration. Active transport Where?Protein channel Which direction?Against concentration gradient fromL to H What substances can carry it out?Hydrophilic only Definition:requiresATPto move/pump ions (chargedparticles) against a concentration gradient from low to high concentration ypotonic Solution– water will move towards highersolute (low water), into cell H Hypertonic Solution– water moves towards higher solute(low water), outside cell Isotonic– equilibrium of solute and solvent betweeninside and outside of cell Protein Synthesis N ucleotide – phosphate, sugar, base (A,C,T,G) Ribosome – site of protein synthesis which occurs on its surface Transcription- DNA (A,C,T,G) template strand creates single mRNA (A,C,U,G) strand in nucleus using free nucleotides via RNA polymerase enzyme mRNA travels out of nucleus to ribosome Translation– tRNA brings anticodon with amino acidto complementary mRNA codon which join together to create a polypeptide chain This amino acid sequence creates a specific Protein Use of genetic code table – know this! Cellular Respiration Mitochondria Part Name 1 Cristae 2 Matrix 3 Inner mitochondrial membrane 4 Outer mitochondrial membrane ames of 3 stages, locations and number of ATP gained / Inputs and outputs of each N stage Stage name Location Net ATP gain Aerobic or Anaerobic 1. Glycolysis Cytosol 2 Anaerobic (no O2) .Citric Acid cycle / 2 Matrix 2 erobic A Krebs cycle Doesn’t have O2 as in input, but is dependent on O2 .Electron 3 Cristae 26 erobic A Transport chain Literally hasO2 as an input. Glycolysis Location Inputs Outputs Cytoplasm 6H C 12O6 (glucose) yruvate P ADP + Pi 2 ATP H (from glucose) Kreb’s Cycle Location Inputs Outputs Matrix yruvate P O2 C ADP + Pi 2 ATP H (from pyruvate) Location Inputs Outputs Inner mitochondrial H 6 ATP 2 membrane / Cristae ADP + Pi H2O O2 Electron Transport Chain Photosynthesis Purpose, when and where it occurs Part Name Role in photosynthesis A Grana Absorb light, split water B Stroma Join CO2 and H to form C6H12O6 Chloroplast – labelling Inputs and outputs of each stage Stage name Location Inputs Outputs .Light 1 Grana ight L H dependent H20 O2 reactions .Light 2 Stroma O2 C C6H 12O6 independent H reactions Digestive system Chemical Digestion - Enzymes tomach:pepsin action, optimal pH 2 andcan withstand acidic (gastric acid) S environment Small intestine:trypsin action, optimal pH 8 mall intestine: S Has a long length which contains a specialised surface, that contains millions of tiny folds calledvilli,giving it a large surface area. On top of that, the epithelial cells lining the small intestine and its villi containmicrovilli on their exposed surface, increasing the surface area even more. Macromolecules –are broken down into their monomersby the enzymes outlined in the table below. Macromolecule Enzyme class required Monomer (absorbable) Protein Protease Amino acid Carbohydrate Amylases Monosaccharide, eg Glucose Nucleic acid Nuclease ucleotide: nitrogen base and pentose N sugar Plant Structure and Function eaf structure: shape (surface area to volume), cuticle, mesophyll, stomata L Palisade mesophyllsite ofphotosynthesisand is locatedon theupper surfaceof the leaf Spongy mesophyllis the main site ofgas exchangeand is ocated on thelower surfaceof leaf Stomataare on theundersideof the leaf Thetop surfaceof the leaf is covered by a thick,waxycuticle(prevents water loss Vascular bundles(including xylem and phloem) arelocated centrally to allow for optimal access by all leaf cells tomata opening and closing: S Guard cells surround stomata and when they fill with water the stomata opens but when water is not available, the guard cells are not filled with water and the stomata close. To close stomata and save water, plants: Actively pump potassium ions out of guard cells Wa ter then diffuses out of the vacuoles and guardcells Ea ch guard cell becomes flaccid, closing the stomata Water Movement oot structure:shape (roots hairs: increases surfacearea to volume), active transport of R minerals to initiate osmosis of water into root hair Vascular tissues: Xylem and Phloem ylem:dead, continuous, one direction, moves water,cohesion/capillary action (water X molecules sticking together) adhesion is water molecules sticking to sides of the vessel Phloem:living, companion cells, two directional, moves sugar and minerals Key knowledge From chromosomes to genomes The distinction between genes, alleles and a genome ene – section of DNA on chromosome G Allele – an alternate form of a gene Genome – full set of DNA/genes in an organism The nature of a pair of homologous chromosomes carrying the same gene loci and the distinction between a utosomes and sex chromosomes omologous chromosomes – carry same genes at the same gene loci, one for mother, one for father H Autosomes – non sex chromosomes, chromosome pairs 1-22 Sex chromosomes – X for female, Y for male The production of haploid gametes from diploid cells by meiosis, including the significance of crossing over of chromatids and independent assortment for genetic diversity aploid – 23 chromosomes in gametes (sperm and egg cells) H Diploid – full set, 46 in all somatic cells/not gametes Meiosis – 2 divisions. 4 cells produced, crossing over and independent assortment create variation Genotypes and phenotypes T he use of symbols in the writing of genotypes for the alleles present at a particular gene locus –eg AA The expression of dominant and recessive phenotypes, includingcodominance (blood types, A, B, AB, O)a nd incomplete dominance (RR=Red, rr=White but Rr=Pink) I nfluences of epigenetic factors, on phenotypes Changes in the way the gene is expressed due to alterations in how tightly coiled the DNA is around histones or via DNA methylation Patterns of inheritance Pedigree charts and patterns of inheritance, including autosomal and sex-linked inheritance ode of M aulty F Affected Healthy . Autosomal dominant – 1 inheritance Allele individuals Individuals look for image on right and the 1. A utosomal trait appearing in every generation Dominant A AA or Aa aa 2. Autosomal recessive – look for two unaffected parents 2. A utosomal B or Bb B producing and affected child b bb Recessive (carrier) 3. Sex linked dominant – more in Female, affected faher s 3. Sex Linked Female ale F M emale M ale pass on to all daughters, not sons (X) XH H XH or X H h H Y X h X X h h Y X Dominant X X 4. Sex Linked emale F Female M ale ale M (X) Xr XR XR or XrX r rY X R Y X Recessive XR Xr 4. Sex linked recessive – more in Males, unaffected carrier females occur Predicted genetic outcomes for a monohybrid cross and a monohybrid test cross Purpose of a test cross – to determine the genotype of a parent displaying the dominant phenotype. How it works: Cross the parent with an organism of known recessive phenotype. A? x aa Possible Outcome 1: If only the dominant phenotype results then the unknown genotype is homozygous dominant. AA x aa = 100% Aa Possible Outcome 2: If dominant and recessive phenotypes result then the unknown phenotype is heterozygous. Aa x aa = 50% Aa and 50% aa ****Always write genotype AND phenotype % at the end of the punnet square
