General Biology Reviewer for 1st Quarter PDF

**GENERAL BIOLOGY REVIEWER FOR 1ST QUARTER** Lesson 1.1: ***Cell Theory  *** **Overview of the Cell** - Cells are **small in size** and can only be viewed with a **microscope**. - Cells have a **high surface area to volume ratio.** **Functions of the Cell** - **Regulation of the Inte...

**GENERAL BIOLOGY REVIEWER FOR 1ST QUARTER** Lesson 1.1: ***Cell Theory  *** **Overview of the Cell** - Cells are **small in size** and can only be viewed with a **microscope**. - Cells have a **high surface area to volume ratio.** **Functions of the Cell** - **Regulation of the Internal Environment** - **Acquisition and Utilization of Energy** - **Responsiveness to their Environment** - **Protection and Support** **Scientists who contributed to the Cell Theory** **Zacharias Janssen** - first primitive microscope **Robert Hooke** - observed cork cells **Francesco Redi** - disproved the spontaneous generation theory. **Anton Van Leeuwenhoek** - discovered bacteria (animalcules) from dental scrapes. **Matthias Schleiden** - all plants are made of cells. **Theodor Schwann** - all animals are composed of cells. **Rudolf Virchow** - all cells come from pre-existing cells. **Principles of the Cell Theory** - Every living organism consists of one or more cells. - The cell is the basic fundamental unit of life. - Cells come from pre-existing cells. **Spontaneous Generation Theory** - Proposed that animals could come from non-living sources (abiogenesis) **Francesco Redi -** maggots developed from eggs laid by flies. **John Needham -** microbes had spontaneously generated from living broth. **Lazzaro Spallanzani -** microbes and spontaneous generation couldn't occur without air. **Louis Pasteur -** used swan-necked flask. Lesson 1.2: ***Major Parts of the Cell*** **3 Major Division of the Cell:** - **Plasma Membrane** - **Cytoplasm** - **Nucleus** Cells consist of both membrane-bound and non-membrane-bound organelles. **Structural Components of the Plasma Membrane** - **Plasma Membrane** - cell's primary barrier; separates the cytoplasm from external environment.  - Contains the following: - **Phospholipids** - **Cholesterol** - **Membrane Proteins** - **Glycoproteins** - **Glycolipids** - **Phospholipids** contains: - Head Region - Phosphate group - Hydrophilic - Tail Region - Two fatty acid chains - Hydrophobic  - **Phospholipids** make the phospholipid bilayer. - Two phospholipid layer - **Phosphate head** faces the cytoplasm - **Fatty acid tails** are sandwiched. - The **fluid mosaic model** describes the membrane structure. **Roles of Lipid Bilayer** **Selective Permeability -** a property of the lipid bilayer; only allows certain molecules to move into and out of the cell **Roles of Membrane Proteins** - **Channel Proteins -** passageway of certain molecules - **Carrier Proteins -** change conformation to transport molecules - **Cell Recognition Proteins -** detect invading pathogens - **Receptor Proteins -** binding of molecules to trigger responses **The Cytoskeletal Elements** - **Cytoskeleton -** consist of a network of protein fibers that gives the cell its structural framework. - Movement of organelles, macromolecules, and chromosomes **Microtubules** - Consist of helically arranged globular protein called **tubulin**. - Radiate from **centrosomes** - Forms spindle fibers which moves **chromosomes** **Microfilaments** - Consist of long fibers of actin protein, thinnest cytoskeleton. - Facilitate cell and organelle movement. - Help change the shape of the cell. **Intermediate Filaments** - Maintains cell shape - Anchors the nucleus **Cytoplasm** - Jelly-like structure composed of the semi-fluid **cytosol** where all organelles and other cellular contents are immersed or suspended. **Cell Wall** - Rigid structure that surrounds the cell membrane; maintains cell shape and prevents them from bursting. - **Peptidoglycan** in bacteria - **Chitin** in fungi - **Cellulose** in plant cells Lesson 1.3: ***Subcellular Organelles*** **The Genetic Control of the Cell** - **Nucleus -** prominent, usually oval structure in a eukaryotic cell; located in almost the center of the cell - **Nucleoplasm** **-** semifluid matrix. - **Nuclear envelope -** separates the nucleus from the cytoplasm - **Nuclear pores -** permits the passage of ribosomal subunits and mRNA out of the nucleus into the cytoplasm. - **Ribosomes -** uses instruction from the nucleus to build **proteins.** - **Free Ribosomes** - found in **cytosol** - **Bound Ribosomes** - attached outside the **E.R** or **nuclear envelope.** **The Endomembrane System** - **Endoplasmic Reticulum** - **Rough ER -** have thousands of ribosomes attached; produces **proteins.** - **Smooth ER** **-** no ribosomes attached; produces **lipids** - **Golgi Bodies -** processing products of the **ER**. - **Lysosomes** **-** digests food (phagocytosis); breaks down damaged organelles (autophagy). - **Peroxisomes -** metabolic assistance; synthesizes and breaks down **lipids**. - **Vacuoles** - storage of water, and various substances. **The Energy Houses of the Cell** - **Mitochondria -** "**powerhouse**" of the cell; houses cellular respiration of the cell. - **Chloroplast -** unique to **plant** and **algae** cells; performs photosynthesis. Lesson 2.1: ***Prokaryotes and Eukaryotes*** **Two Types of Cells** - **Prokaryotes -** includes all organisms of domain **Archaea** and **Bacteria** - **Eukaryotes -** includes domain **Eukarya**; which includes plants, animals, fungi, protists. **Distinguishing Features of Prokaryotic and Eukaryotic Cells** +-----------------------+-----------------------+-----------------------+ | | **Prokaryotes ** | **Eukaryotes** | +=======================+=======================+=======================+ | **Presence of | Nucleoid Region | Nucleus | | Nucleus** | | | +-----------------------+-----------------------+-----------------------+ | **Cell Wall** | Present in almost all | Present in most | | | prokaryotic cells  | eukaryotic cells (not | | | | in animals and most | | | Made of | protist) | | | **peptidoglycan ** | | | | | **Cellulose** in | | | | plants; | | | | | | | | **Chitin** in fungi | +-----------------------+-----------------------+-----------------------+ | **Cell Membrane** | Has sterol-like lipid | **Cholesterol** in | | | called **hopanoid**. | animals | | | | | | | | **Phytosterol** in | | | | plants | | | | | | | | **Ergosterol** in | | | | fungi | +-----------------------+-----------------------+-----------------------+ | **Endomembrane | **None** | **Present** | | System** | | | +-----------------------+-----------------------+-----------------------+ | **Ribosomes** | All ribosomes can be | Can be found in | | | found in the | cytoplasm, outer | | | cytoplasm | nuclear membrane, | | | | rough E.R., | | | **70S** Ribosomes | mitochondria and | | | | chloroplast | | | | | | | | **80S** Ribosomes | | | | (Mitochondria and | | | | Chloroplast have | | | | **70S**) | +-----------------------+-----------------------+-----------------------+ | **Shape of DNA** | **one** covalent, | **more than one** | | | closed, circular DNA | linear DNA with | | | | histone | +-----------------------+-----------------------+-----------------------+ | **Number of | have **only one** | have **more than | | chromosomes ** | chromosome and an | one** chromosome | | | extrachromosomal DNA | | | | called **plasmid**. | | +-----------------------+-----------------------+-----------------------+ | **Cell Size** | 0.1 to 5 μm | 10 to 100 μm | +-----------------------+-----------------------+-----------------------+ | **Mode of | **Binary Fission** | **Mitosis** or | | Reproduction** | | **Meiosis ** | +-----------------------+-----------------------+-----------------------+ | **DNA Replication** | Two **opposing** | **Multiple points** | | | directions | of origin | | | | | | | Don't have | Has **telomerase** | | | **telomerase** | | | | | Replicates in | | | **Continuously** | **S-Phase** | | | replicate | | +-----------------------+-----------------------+-----------------------+ | **Transcription and | **Both** occur in the | **Transcription** in | | Translation** | **cytoplasm** | **nucleus** | | | | | | | | **Translation** in | | | | **cytoplasm** | +-----------------------+-----------------------+-----------------------+ Lesson 2.2: ***Structure of Animal Cell*** **Types of Animal Tissues** - **Epithelial Tissue -** forms the inner and outer lining of organs - Simple Squamous  - Simple Cuboidal - Simple Columnar - Pseudostratified Columnar  - Stratified Squamous  - Stratified Cuboidal  - Stratified Columnar  - **Connective Tissues** - vary with the composition of their extracellular matrices and types of cells they consist of. - Bone or osseous tissue - Cartilage - Dense Connective Tissue - Loose Connective Tissue - Blood - **Muscle Tissues -** elicit movements. - Skeletal muscle - Smooth muscle - Cardiac muscle - **Nervous Tissues -** main tissue component of the nervous system - Astrocytes - Microglial cells - Ependymal cells - Oligodendrocytes - Satellite cells - Schwann cells Lesson 2.3: ***Structure of Plant Cell*** **Meristematic Tissues ** - found in the growing area of plants **Apical meristem -** primary growth **Lateral meristem -** secondary growth **Permanent Tissues** - responsible for photosynthesis, support, transport of water and nutrients. **Simple Permanent (Epidermal)** - **cuticle** - prevents water loss - **root hairs** - help in increasing absorption capacity - **trichomes** - hair-like outgrowths that prevent water loss - **guard cells** - regulate closing and opening of stomata - **stomata** - aids in exchange of gases **Simple Permanent (Ground)** - **Parenchyma** - synthesis and storage of food - **Collenchyma** - furnishing flexible support - **Sclerenchyma** - strengthen seed coat and used to making ropes **Xylem** - transports water throughout the plant's body. **Phloem** - transports nutrients throughout the plant's body. Lesson 2.4: ***Structure of Modified Cell*** **Specialized Cells and Cell Structures in Animals** **Microvilli -** increase the surface area for the absorption of nutrients **Cilia** - prevents mucus, bacteria, dirt,  from entering the lungs **Stereocilia -** responsible for sensation **Flagella** - provide motility to cells **Basal Infoldings** - for increasing surface area and for ion and fluid transport **Hemidesmosomes -** responsible for attachment **Cell Junctions** - serves as connections between adjacent cells - Tight Junction - Adherens Junction - Desmosomes - Gap Junction **Red blood cells -** aid in diffusion of gases, lacks nucleus, transports oxygen around the body. **White blood cells** - responsible for the body's defenses - Neutrophils - Lymphocytes  - T-Lymphocytes - B-Lymphocytes - Monocytes - Eosinophils - Basophils **Egg cells** - largest cells in the human body, for sexual reproduction **Sperm cells** - for reproduction **Specialized Cells and Cell Structures in Plants** **Trichomes -** prevents insect attacks, shading leaves, trapping insects **Root hairs** - facilitate the absorption of water **Mesophyll layer** - made of spongy and palisade cells **Xylem -** transport of water **Phloem** **-** transport of nutrients Lesson 3.1: ***Cell Cycle and Cell Division*** **Cell Cycle** - life cycle of a cell **Cell Division** - how cells divide **DNA** - deoxyribonucleic acid, genetic material of the body **Chromatin -** complex of DNA and proteins **Chromosome** - highly condensed form of chromatin **Chromatids** - halves of chromosomes **Stages of Cell Cycle ** **Interphase - G1 -** Highest rate of protein synthesis **Interphase - S -** DNA Replication  **Interphase - G2 -** still protein synthesis **M** - **Meiosis** for sex cells, **Mitosis** for body cells **Cytokinesis** - division of cytoplasm, **cleavage furrow** in animals, **cell plate** in plants. **Cell Checkpoints** **G1 Checkpoint** **G2 Checkpoint** **M Checkpoint** Lesson 3.2: ***Mitosis*** DNA is in the form of **chromatin** in interphase, then condenses into **chromosomes** during mitosis **Diploid -** 46 chromosomes  **Haploid -** 23 chromosomes **Mitosis** - division of body cells **Stages of Mitosis** **Prophase** - Chromosome condensation, spindle formation **Prometaphase -** begins after breakdown of nuclear envelope **Metaphase -** alignment of chromosomes in metaphase plate **Anaphase -** separation of the sister chromatids to opposite poles **Telophase -** chromatids decondense, spindle disappears, production of two daughter cells. The result is two daughter cells that are **diploid**. Lesson 3.3: ***Meiosis*** **Meiosis** - division of sex cells/gametes Sex cells have **haploid** sets of chromosomes Reduction from **46** chromosomes to **23** **Stages of Meiosis** **Meiosis I -** Reductional division **Prophase I -** the genetic material starts to condense - **Synapsis -** homologous chromosomes align from side to side - **Tetrad -** four homologous chromosomes  - **Crossing over** - exchange of segment between homologous chromosomes - **Recombination -** new DNA molecules are produced from different segments of same parent DNA molecule, cause of genetic diversity **Prometaphase I -** nuclear envelope disintegrates, meiotic spindle formation **Metaphase I -** alignment of tetrads in the middle of the cell or metaphase plate **Anaphase I -** segregation of homologous chromosomes to opposite poles **Telophase I and Cytokinesis -** may form nuclear envelope, formation of two daughter cells with a set of haploid chromosomes **Meiosis II -** Equational division **Interkinesis/Prophase II -** new spindle forms around the chromosomes  **Metaphase II -** chromosomes lined up to the metaphase plate **Anaphase II -** segregation of sister chromatids to opposite poles **Telophase II -** results in four haploid daughter cells **Differences of Meiosis and Mitosis** - **1** round in mitosis, **2** rounds in meiosis - **Meiosis** produces haploid cells, **Mitosis** produces diploid cells - **Meiosis** in sex cells, **Mitosis** in body/somatic cells. Lesson 3.4: ***Significance and Implications of Meiosis and Mitosis*** **Significance of Mitosis** - maintenance of genetic material - growth and development  - repair and recovery - asexual reproduction **Genome** - complete set of genetic material in somatic cells **Maintenance -** genome must be maintained to have proper biological functions **Mitosis -** division that allows complete set of genetic material to be inherited **Growth in Mitosis** - organism's maturity - increase in size - increase in cell number - attributed to mitosis Old and damaged cells are replaced through **mitotic division**. **Hydra** - produces asexually through budding **Significance of Meiosis** - reduction of genetic material and sexual reproduction - genetic diversity - inheritance - survival **Reduction of Genetic Material and Sexual Reproduction** - produces gametes - allows both parent to contribute genetic material - restoration of chromosomes during fertilization **Roles of Meiosis in Survival** - increase in the probability of survival - increase in genetic diversity - crossing over as a mechanism of genetic recombination  - production of new genetic variants **Hayflick Limit -** certain number of times that cell can divide before being too aged. Lesson 3.5: ***Disorders and Diseases related to Cell Malfunction during Cell Cycle*** **Errors in Cell Cycle** **Mitotic and Meiotic Errors** - **Nondisjunction** - failure of the chromosomes or chromatids to separate properly - **Mitotic nondisjunction -** in mitosis when pairs of chromosomes do not separate properly **Cell Cycle Disorders and Diseases** - **Polyploid -** abnormal number of sets of chromosomes  - **Aneuploid -** abnormal number of chromosomes  - **Cancer** - abnormal cell growth and spreads across the body - **Nondisjunction Disorders** - **Down Syndrome -** karyotype of a person with **Trisomy 21** - **Patau's Syndrome -** karyotype of a person with **Trisomy 13** - **Turner Syndrome -** karyotype of a person having only **one X chromosome ** - **Mosaicism -** Skin discoloration in Klippel - Tréneunay syndrome - **Alzheimer\'s Disease** - **Microcephaly -** occurs when head is smaller than normal during birth - **Psychiatric diseases** - **Bipolar disorder** - manic and depressive episodes - **Major depressive disorder** - severe depressive episodes - **Schizophrenia -** interferes with a person's sense of reality Lesson 4.1: ***Structure and Functions of the Cell Membrane*** **Phospholipid Bilayer** - barrier to the passage of molecules and ions into and out of the cell - **Hydrophilic Head** - **Hydrophobic Tail** **Molecules Embedded in Cell Membrane ** - **Cholesterol** - prevents membrane from becoming too fluid at high temperatures - prevents membrane from becoming too solid at low temperatures - Fluidity imparts flexibility and synthesizes membrane proteins - Presence of double bonds in fatty acids helps maintain membrane fluidity **Membrane Proteins** - **Transport -** either carrier or channel proteins - **Adhesion** - fasten adjacent cells together - **Recognition** - help in recognizing invading pathogens - **Receptor** - allows only specific molecules to bind to them **Carbohydrate Chains** - **Glycolipids** (carbohydrate + lipid) - **Glycoprotein** (carbohydrate + protein) Cell membrane has an ability called **selective permeability** that only allows specific molecules to go into and out of the cell. Lesson 4.2: ***Cell's Transport Mechanism I: Diffusion and Osmosis*** **Diffusion** - **Simple Diffusion** - the movement of molecules from high solute concentration to low solute concentration to achieve state of equilibrium  - **Facilitated Diffusion** - movement of ions and water outside transported across the cell membrane through channel proteins **Osmosis** - Transport of **water** from high solute concentration to low solute concentration - **Tonicity ** - concentration of solute in fluids - concentration of solute - ability of surrounding solution to cause a cell to gain or lose water - isotonic, hypotonic, hypertonic - **Isotonic** - equal solution in and out of the cell - Flaccid - **Hypotonic -** low solute concentration and high water concentration (can cause cell to swell or burst) - Turgid - **Hypertonic -** high solute concentration and low water concentration (can cause cell to shrink or shrivel) - Plasmolyzed Lesson 4.3: ***Cell's Transport Mechanism II: Active and Facilitated Transport*** **Active Transport ** - movement of molecules against the concentration gradient with **energy expenditure.** - have **large number of mitochondria** - **Sodium-potassium Pump ** - initially binds to **three sodium ions,** then phosphate is added, then **two potassium ions** bind, then release inside the cell. - **Calcium Pump** - do not need to bind to **second ion** **Facilitated Transport** - transport of molecules down the concentration gradient with the **aid of membrane transport proteins.** - **Glucose Transporters** - **Ion Channels** Lesson 4.4: ***Bulk or Vesicular Transport*** **Vesicle -** consisting of cytoplasm and enclosed by lipid bilayer **Golgi Bodies -** produces vesicles **General Mechanism of Bulk Transport** - **Budding** - **Scission** - **Uncoating** - **Translocation** - **Tethering** - **Fusion** **Types of Vesicular Transport** - **Phagocytosis** - **Pinocytosis ** - **Receptor-mediated endocytosis** Lesson 4.5: **Endocytosis and Exocytosis** **Types of Exocytosis** - **Constitutive -** transport of molecules outside the cell through vesicles, vesicle then fuses with the plasma membrane. - **Regulated -** transport of molecules outside the cell because of triggered signals. **Endocytosis** - transport of molecules into the cell membrane - **Phagocytosis -** defense and repair for the human body, involves **food molecules (vacuoles).** - **Pinocytosis -** functions for ingestion, involves **liquid or small molecules (vesicles)** - **Receptor-mediated Endocytosis** - regulation of molecules of the cell, uses a receptor protein to recognize compatible molecules. Lesson 6.1: ***Enzyme Structure and Function*** **Enzymes -** biomolecules that helps in speeding up the chemical reactions that occur in cells. **Catalysis -** speeding up of reaction rates. **Transition state -** lowering of activation energy **Substrate** - molecule that the reactions of which are catalyzed by the enzymes. **Product -** produced when enzyme and substrate are bound to each other. **Lock and Key -** allows only that type of binding to occur between these two molecules. **Induced Fit -** modifies the active site that allows substrate to fit. **Enzymes Role in the Body** - **Digestion** - amylase, trypsin, pepsin help in breaking down molecules for digestion - **Cell Division -** helps in modifying proteins for cell division - **Nervous function -** Acetylcholinesterase helps breakdown acetylcholine - **DNA Replication -** helicase and DNA polymerase help in DNA replication. Lesson 6.2: ***Enzyme in Biological Systems*** - **Anabolism -** synthesizes complex molecules into simpler ones. - **Catabolism -** breaking down larger molecules into simpler ones. - **Reduction Reaction -** gaining electrons - **Oxidation Reaction -** losing electrons - **Redox Enzymes** - Enzymes that play important role in redox reactions - **Free Radicals -** uncharged atoms or molecules. Lesson 6.3: ***Factors that affect Enzyme Regulation and Metabolism*** **Saturation Level ** - **Chemical reactions** rely on collisions - **Saturation Point** - maximum reaction rate, and increasing the amount of substrate will not affect the reaction rate any further. - This only occurs on catalyzed reactions. **Factors that Affect Enzyme Activity ** - **Temperature** - **Increasing** the temperature **increases** also the rate of enzyme reactions. - Excessive high temperatures can break bonds in molecules leading to **denaturation.** - **pH Level** - Enzymes also have **optimal** **pH level.** - **Substrate Concentration ** - Highest reaction rate is achieved when **all the enzymes have available substrates for binding and catalysis.** - Very high concentration with not enough enzymes will **not be efficient.** - **Enzyme Concentration**  - **Higher enzyme concentration** can ensure that there are more catalyst available to speed up a particular chemical reaction. - Only increases reaction rate as long as **there are still substrates available.** - **Inhibitors** - substances capable of slowing down or terminating catalytic reactions. - **Competitor Inhabitors -** bind to active site. If concentration is high, then reaction rate slows down even further - **Noncompetitive Inhabitors -** bind outside cell's active site. Reduces active site capacity to bind with substrates. - **Chemical Modifications** - **Phosphorylation** - addition of phosphate groups - **Dephosphorylation** - removal of phosphate groups.