General Biology Midterms.pdf

General Biology Midterms - Maintain an optimal environment for the cellular organelles. Chapter 1: Lesson 1: Cell e. Ri...

General Biology Midterms - Maintain an optimal environment for the cellular organelles. Chapter 1: Lesson 1: Cell e. Ribosome Robert Hooke – the one who discovered the cell - Tiny spherical organelle Postulates of Cell Theory: - make protein 1. All living things are composed of one or more cells. f. Plasmid 2. The cell is the basic unit of life. 3. All new cells arise from existing cells - carry a small number of non-essential genes - used in genetic engineering to amplify certain genes g. Pili - hair-like structure for motility - Involved in adherence to surfaces h. Flagellum - For cell motility/movement i. Nucleoid - Contain DNA - Regulates the growth, reproduction, and function of the prokaryotic cell Similarities of Prokaryotic and Eukaryotic II Eukaryotic Cell Both have the following organelles: Similar Organelles in Plant and Animal Cells a. Cell wall b. Plasma membrane a. Plasma Membrane c. Cytoplasm - Controls passage of molecules d. Ribosome Have DNA - provide protection Some have Flagella - Semipermeable I. Prokaryotic Cell b. Cytoplasm Shapes of Bacteria: Thermopile - high - Medium for chemical reaction Cocci - round temperature Bacilli - oval/oblong Halophile - high salinity - Carries the organelles Spirilla - spiral Acidophile - high acidity c. Peroxisome - Contain digestive enzymes a. Capsule d. Mitochondria - The sticky outermost layer - The ‘powerhouse’ of the cell - Made of polysaccharides - Production of ATP b. Cell Wall e. Golgi Body - Maintains the cells shape - Modify, pack, and export proteins to the parts of - Protect the interior of the cell the cell c. Plasma Membrane f. Vacuole - Separates the cytoplasm from outside - in animal and plant, it stores water environment - in plant, it takes up to more than 30% of the cell’s - Semipermeable volume d. Cytoplasm - Gel-like fluid g. Rough Endoplasmic Reticulum Chapter 1: Lesson 2: Cell types and Modifications - Near the nucleus of the cell - with Ribosome - Synthesize the protein h. Smooth Endoplasmic Reticulum 4 types of cell - Away from the nucleus 1. Epithelial - Form covering layers of organs and other cells - no ribosome - Barrier for pathogens, fluid loss, and - Synthesize the Lipid mechanical injuries. - Ex: Skin Cells i. Ribosome - Help manufacturing proteins for the cell, following the instructions of the nucleus j. Intercellular Junctions - Regions of contact - provide structural means by which groups of cells (Stratified if two or more layer) can adhere and interact 2. Nerve Cell k. Nucleus - Specialized for communication - Responsible for one’s consciousness - the big circle inside the cell - Never multiply in one’s lifetime - it is the brain of the cell - contains the genetic material or DNA l. Cytoskeleton - shape and internal organization of the cell - provide mechanical support during cell division and movement 3. Muscle Cell m. Lysosome - Also known as Myocytes. - Responsible for movement - it is the digestive center of a cell - Produces enzymes to break down food particles and recycle worn out components of the cell. Unique organelles in Plant Cell a. Chloroplast - Contain a green pigment (chlorophyll) that traps sunlight and converts it into sugars. b. Amyloplast Cardiac - It is the storage of starch granules c. Cell Wall - The muscle fibers that comprise the - It is located outside the cell membrane myocardium - Provide rigidity, strength, protection against - Present only in heart muscle mechanical stress and infection. - Involuntary Unique organelle in Animal Cell Skeletal a. Centrosome - Make up the muscle tissues connected to the - For the production of microtubules skeleton - Important in locomotion or movement - Voluntary Smooth Plasmodesmata - Involves in a process called peristalsis inside - Small pits that link one plant cell to another the intestine Pseudopods Peristalsis - movement of food inside the intestine - Bulge outward to move the cell or engulf prey. - Transport of food Extracellular Matrix - Present in stomach, intestine, and vessel walls - Involuntary - Compound secreted by the cell wall 4. Connective tissue cell - Cell wall in plant cells - Provide structural strength to the body - Glycoprotein in animal cells - Help connect other cells and tissues a. Blood Cell Cell-Cell Junctions - Always motile and never stay in one place - To join cell in long term association - Have limited lifespan and never multiply to form new cells b. Flat Cells - Also known as adipose cell or adipocyte. - Functions: o Provide protection o Provide insulation o Store energy c. Cartilage cells o Similar to bone cells but the surrounding material is just loose and flexible. o Free bendable a. Tight Junction d. Bone Cells - Regulate water movement o Toughest body cell b. Adhering Junction o Bound together by: Calcium and - Anchoring junction that fasten cells to one Phosphate another o Function: Give strength, support, and c. Gap Junction framework - Closable channels that connect the cytoplasm Lesson 2: Cell Modification of adjoining cells. d. Desmosome/Hemidesmosome Cell Modification - Links between cytoskeleton and ECM components - Are specialized of modifications re-acquired - Primarily composed of keratin, integrins and by the cell after cell division that helps the cell cadherins in different beneficial ways Chapter 2: Lesson 1: Cell Cycle Microvilli Cell Cycle - Cytoplasmic extension to increase the surface area I. Interphase o Cell Grows. Nerve Cell o DNA is replicated o Cell prepares for division - It is elongated to facilitate the transmission of o It includes: impulses ▪ G1 phase Red Blood Cell ▪ S phase ▪ G2 phase - Have a biconcave-disc shape and highly 3 Portions in Interphase deformable 1. G1 Phase o Decision-making step. Chromatophores o Cell increase in mass and organelle - Contain bioluminescent pigments to facilitate number. changing of colors. o Animal cell are diploid. 2. S Phase Nematocytes o DNA is replicated. - Stinging cell containing needle-like structure o Centrosome is duplicated. to inject toxic substance. 3. G2 Phase o Cytoskeleton is dismantled. Root Hairs o Additional cell growth. - Elongated o Final preparation for mitotic phase. - Facilitate Absorption  4 Mitotic Phase Spindle fibers (NK) Lengthen and elongate the cell o Duplicated chromosomes are aligned, separated, and move to opposite poles of the cell. 4. Telophase o Cell divides into two new identical daughter cells. Chromosomes Arrived at the pole o It includes: ▪ Karyokinesis – division of Nuclear envelope Appears cell nucleus during mitosis Spindle fibers Disappears/ breaks down ▪ Cytokinesis – Cytoplasm + Separation = separation II. Cytokinesis of cytoplasm - Cleavage furrow (Animal Cell) In some cells - Cell Plate (Plant Cell) - Meiosis - G0 Phase: Not applicable to all *PRODUCT: 2 identical diploid daughter cells o Cells are not actively preparing to divide. o Resting phase MEIOSIS o The cell is in quiescent (inactive) stage that occurs when cells exit Chromatin > Chromosome (composed of 2 sister Chromatid) the cell cycle. ▪ Temporary- cells that remain in G0 until Parts of Chromosome: external signal triggers the onset of G1. ▪ Permanent- cells that never or rarely divides (mature cardiac muscle and nerve cells). II Mitotic Phase 1. Prophase Chromosome Condenses and becomes visible Spindle fibers Appears from centrosome Nuclear envelope Breaks down Nucleolus Disappears Centrosome Move to poles 2. Metaphase Spindle fibers Fully developed Centrosome Arrived at the poles Prophase 1 Chromosomes Lined up in the middle Chrosmosome – Condenses Each sister chromatid Attached to spindle fiber Spindle Fiber – Appears from centrosome Kinetochore - attached to spindle fibers (protein sa chromosomes) Homologous Chromosome (meaning 4) – Bind firmly Non-kinetochore (NK) - no protein attached (tetrad) and from Chiasmata. 3. Anaphase Cohesion protein Breaks down Chromosomes Pulled towards the poles  Mitosis – Replacement of worn out cells Chiasmata - Crossing over and exchange of genetic Mitosis – Keeping chromosome number constant in a body material occurring. cell Recombinant – crossing over Non-Recombinant – no crossing over Meiosis – Production of sex cells Spermatogonia and Oogonia Metaphase 1 Properties Spermatogonia Oogonia Production Rate Millions/day 1/month Homologous Chromosome – aligned at middle Location Testes Ovary Anaphase 1 Motility motile Non-motile Spindle Fiber – pull homologous chromosome apart Non-Disjunction Sister Chromatid – still attached to centromere Xxx – metafemale and move to opposite poles Xxy – klinefelters syndrome Telophase 1 Xo – turners’ syndrome Sister Chromatid – Arrived at poles and Yo – not viable decondense Apoptosis Nuclear Envelope – Appear - Programmed cell death Product: 2 Diploid daughter cells - Different from unintentional cell death caused Meiosis 2 by injury or infection - Body’s way to eliminate cell that no longer Prophase II function - During apoptosis: Nucleus Shrinks, Sister Chromatid – Condense Chromosomes disintegrate, Mitochondria Spindle Fiber – Appear stop supplying energy and cell collapses Nuclear Envelope – Breaks down Phagosytosis Metaphase II Phago – to eat Sister Chromatid – Pulled apart Pino – to drink Anaphase II Cancer – Uncontrolled Cell division Sister Chromatid – pulled apart Tumor – Disorganized solid mass of cell formed from rapid cell division Non-Kinetochore Microtubules – Elongate the cell Types of tumor Telophase II Benign Tumor – Harmless or not and can probably be cured Chromosome – arrived at pole and decondense Malignant Tumor – Tumor that break away and is Nuclear envelope – appear more difficult to get rid of Product: 4 Haploid daughter cells Metastasize – kumalat Crossing over Facts about cancer cell: – genetic material exchange between non-sister - Do not perform specialized function but hinder chromatids the functions of other normal cell - Compete for nutrients and blood supply Importance: Facilitate the genetic recombination Recombination - Process by which the pieces of DNA are broken and recombined to produce new combination of alleles Importance: genetic variation Prophase – a phase in meiosis that does crossing over and recombination Membrane Transport