Ib Biology Higher Level - Cells

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Bio Review – Cells
Cell Theory
2.1.1
* All living things are made of cells
* Smallest unit of life
* Existing cells from pre-existing cells
* Contain a blueprint for growth, development, behavior
* Site of all chemical rxns
2.1.2
* Abiogenesis
* Living from non-living matter
* Robert hook
* Compound microscope + observed cork “cells”
* Anthony van Leeuwenhoek
* Observed blood cells and other “living” cells
* Louis Pasteur
* Proved abiogenesis wrong. Only airborne microbes contaminating * Experiment
* Broth sterilized, exposed to air or protected by swan-neck flask, only exposed broth contaminated. 2.1.3 – Unicellular organisms carry out all the functions of life * Metabolism
* Response
* Homeostasis
* Growth
* Reproduction
* Nutrition
2.1.4
* Molecules 1nm
* Membrane 10nm
* Virus 100nm
* Bacteria 1um
* Organelles >10um
* Cells < 100um
2.1.5 – N/A
2.1.6
* Increase size = decrease SA: Volume
* Ratio decreases = exchange decreases
* Limits cell size for efficiency
* Rate of heat/waste production + nutrient consumption = function of volume * Exchange rate = function of SA
2.1.7 – Multicellular organisms show emergent properties
* Whole is greater than the sum of its parts

2.1.8
* Nucleus – DNA – chromosomes – genes
* Differentiation occurs when genes are “switched on” = determines development * Differences btwn cells by division of labor
* Cost of specialization
* Positive = efficiency
* Negative = Dependant on others cells
* Totipotent = Become new organism or any cell within organism * Pluripotent = Become and cell within organism
* Factors effecting = location, environment, activated genes * Multinucleate = 2+ nuclei
2.1.9 – Stem cells retain ability to divide and can differentiate along different pathways 2.1.10
* Restore isolative tissue to neurons in rats = increased mobility Prokaryotic Cells
2.2.1

2.2.2
* Capsule – Slime layer, stick to things, blocks dryness * Cell Wall – Protects, shape
* Plasma Membrane – semi-permeable bi-layer, controls molecule movement * Cytoplasm – fluid medium, processes occur
* Pili – hair-like growths, attachment, plasmid transfer * Flagella – longer, motility
* Ribosomes – protein synthesis
* Nucleoid – single, circular DNA strand, free floating, not protein bound, contains all info to replicate * Plasmid – circular DNA molecules, independent, contain genes 2.2.3 – Prokaryotic cells divide by binary fission

Eukaryotic Cells
2.3.1

2.3.2
* Plasma membrane – semi-permeable bi-layer, controls molecule movement * Cytoplasm – fluid medium
* Mitochondria – Cell Respiration, ATP
* Centrosome – Microtubule assembly
* Nuclear Membrane – Protects DNA
* Lysosomes – Breakdown + transport proteins, lipids, carbs * Smooth ER – Production + transport lipids
* Vacuole - storage organelle (High SA:V)
* Ribosome – Protein synthesis
* Rough ER – Protein development + transport
* Nucleus – Holds DNA, controls cell function
* Nucleolus – Ribosome synthesis
* Nuclear Pore – Allows communication btwn nucleus and cell * Golgi Apparatus
* Stores, modifies + packages proteins into vesicles
2.3.3 N/A
2.3.4
Pro| Euk|
DNA ring (no proteins)| DNA with protiens|
Free DNA| Enclosed DNA|
No mitochondria| Mitocondria|
Only 70s| Both ribosomes|
No compartmentalization| Organelles = compartmentalization| > 10um| < 10um|

2.3.5
Plant| Animal|
Chloroplasts present| Not present|
Large central vacuole| Small if present|
Angular shape| Round shape|
2.3.6
* Cell Wall (Plants)
* Maintains shape, prevent excessive water uptake, holds up against gravity (tugor) * Extracellular Matrix (Animals)
* Formed by glycoprotein
* Support,...
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