CHAPTER 2: From Cells to Systems
Important topics in cell biology: * Cell theory: 1. All organisms are composed of cells and cell products 2. The cell is the simplest structural and functional form of life 3. An organism’s structure and all of its functions are ultimately due to the activities of cells 4. All cells arise from pre-existing cells 5. All cells share fundamental similarities and metabolic mechanisms * Cell structure: * About 210 different cell types in the human body, including: squamous, polygonal, cuboidal, columnar, spheroid, discoid, stellate, fusiform, fibrous * Fluid-mosaic model of the plasma membrane because the double phospholipid membrane is more liquid than solid * Microvilli- tiny folds of the plasma membrane found on the apical surface of the cells that line the small intestine, and in some other parts of the body. Increase the SA of the cell, enabling a rapid rate of transport of nutrient molecules into the cell * Cilia- tiny hairlike structures that protrude from the plasma membrane into the ECF. Motile cilia are found in places like the respiratory tract & uterine tubes where they move substances past the tissue (“9+2” arrangement of microtubules) * Flagella- found only on sperm cells, it is a single, whiplike structure that propels the sperm through its environment (also has the “9+2”…) * Functions of specific organelles * The cytoskeleton: a latticework of protein microfilaments and microtubules that function as the skeleton of the cell. Makes parts of the cell rigid, serves as a transport system within the cell, can produce cell movement * Mitochondrion: the sites for most of the energy production within a cell. * Contain their own DNA * All mitochondria come from the mother’s egg cell * Endoplasmic reticulum (ER): Two types 1. Rough ER: contain ribosomes (“protein factories”) that read mRNA codes then sends vesicles containing the newly made protein to the Golgi complex… 2. Smooth ER: synthesizes other materials, detoxification, Ca2+ storage. (no ribosomes, no protein synthesis) * Golgi complex: a network of stacked, flattened membranous sacs withing the cytoplasm of cells. * Takes vesicles containing protein from the rough ER and continue synthesis * Sends finished products out as: * Lysosomes which stay in the cell or as * Secretory vesicles that take proteins out of the cell * Nucleus: contains all the instructions for protein synthesis in the form of DNA. * DNA consists of nucleotides which form 2 strands connected together by H-bonds. The sequence of nucleotides gives us our genetic information * Chromatin is the long and threadlike form of DNA and protein that serves as the functioning genetic material within the nuclei of nondividing cells * Chromatin is spooled onto proteins to form nucleosome particles which condense into a more compacted form identified as: * Chromosomes are compacted chromatin visible through a microscope that contain regulatory proteins as well as DNA * Membrane transport* * Energy transduction* * Cell-cell signaling* * Cell cycle and its regulation
3 Types of RNA: 1. Messenger RNA (mRNA): a complementary copy of a gene that codes for the structure of a protein 2. Transfer RNA (tRNA): contains 3 nucleotides at one end which match up with a codon of mRNA (anticodon) and an AA on the other end. Transfers AAs to the messenger RNA, translating the nucleotide base into an AA sequence 3. Ribosomal RNA (rRNA): make up part of the structure of ribosomes
Making Proteins (Transcription and Translation):
DNA acts as a template for the synthesis of RNA: * A gene is a region of DNA that codes for a polypeptide chain * Transcription: The process by which mRNA is
Science Study Notes 2.1 Plant and animal cells 2.2 observing plant and animal cells through a microscope 2.3 the importance of cell division Cell division is important because it is the way healthy body cells are expected to function and aid in the growth of different body parts.. Without cell division the body dies. 2.5 the cell cycle 2.7 cell division gone wrong Cancer cells are cells gone wrong — in other words, they no longer respond to many of the signals…
is regulated by neurotransmitters released from nerve cells in the brain Neurotransmitter release influences behavior and hormones, hormones influence release of neurotransmitters through chemical messengers The Body’s Three Communication Systems Nervous system, endocrine system, and immune system Nerve cells communicate through release of neurotransmitters Endocrine glands communicate through hormones Immune system communicates through cytokines Systems are not independent and interact Non-cognitive…
Cell Manual (Totipotent cell 1st edition) Table of Contents What you are……………………………......……………………………………............………3 Endocrine system…………………………………………………………………………….......4 Endocrine system cont………………………………………………………………………….5 What you could become……………………………………………………………...…....…6 What you could become cont……………………………………………………………..7 Nervous system…………………………………………………………………………………..8 Nervous system cont…………………………………………………………………………9 What you could become………………………………………………………………....10…
peripheral nervous systems The nervous system consists of a complex network of nerves and cells. Through the complex networks of nerves and cells the messages carry from and to the brain and spinal cord to different parts of the body. The nervous system comprises both the Central nervous system and Peripheral nervous system. The Central nervous system is counting of the brain and spinal cord and The Peripheral nervous system is counting of the Somatic and the Autonomic nervous systems. Commonly, the…
The Immune System The immune system is the most incredible part of our body. It has the task of keeping the body healthy by destroying pathogens and disease-producing organisms, and by neutralizing their toxins. The immune system employs the services of the skin, mucous membranes, hair, cilia, saliva, urine and other natural means of waste disposal to keep the body free of illness and pathogens, For instance, should foreign bacteria enter the body, the immune system will employ cells in the body…
Cells are specialised to perform a specific function at an optimum efficiency. These cells are usually found in groups of other similar cells to them which is called a tissue. In animal cells there are four main tissue categories, these are epithelial tissues- tissues used in lining of the uterus, next are connective tissues-hold structures in the body together, then there is muscle tissue-used in the actuation of movement of limbs and body parts, finally there is the nervous tissue-communication…
Homeostasis and Body Temperature The Transport Systems Cardiovascular System: pumps blood to and from capillaries for exchange of gases, nutrients and wastes occur. Red Blood Cells: carry oxygen Platelets: Clot blood Lymphatics: collect excess tissue fluid and purify lymph. Lymph: a clear-to-white fluid made of: White blood cells The Maintenance Systems Respiratory system: brings in O2 and removes CO2 from the blood Digestive system: digest nutrients and removes waste Liver: manufactures products…
correct answer below. 1. The lungs, nose, and trachea are part of which organ system? a) Digestive b) Respiratory c) Muscular d) Circulatory 2. The pancreas is part of the ____________ system. a) digestive b) nervous c) respiratory d) cardiovascular 3. The frog has a ____ chambered heart. a) 5 b) 3 c) 4 d) 2 4. The blood cells that carry oxygen are the: e) platelets f) red blood cells g) white blood cells h) antigens 5. Which of the following is the cell’s main energy providing compound…
P1) Components of a cell – There are many different parts to a cell. There is a nucleus which is a small circle and contains genetic information including DNA. It also contains what happens in the cell. The cell also contains a plasma membrane which is the outside of the cell. It is made up of a Hydrophilic (which attracts water) and Hydrophobic structure (which repels water) and allows things in and out of the cell. Next, there is the mitochondrion which is where the chemical reactions take place…
Science 10 – Biology Chapter 1 – Tissues, Organs, and Systems of Living Things (Cells) 1.1 – Cell Structure Microscopy – The science of using microscopes to view samples or objects. Micrograph – A photograph taken with a microscope. Microscopes: * Leeuwenhoek Microscope – 250x. Hand held. * Fluorescence – 1500x. Fluorescent stains, glow. * Phase-Contrast Microscope – 1500x. Light Contrast. * BrightField/DarkField – 2000x. Bright/Dark background. * Scanning Electron Microscope…