Flashcards
Anatomy - The Cell
Cards in this deck (72)
- 1The cell?Basic structural and functional unit of the body, can perform all basic functions of life
- 2Cell (plasma) membrane?Outer boundary of cell; is selectively permeable
-Divides intracellular fluid (ICF) from extracellular fluid (ECF) - 3Parts of the cell (plasma) membrane?Phospholipid bilayer, membrane proteins, membrane CHOs, microvilli
- 4Divisions of membrane proteins?Integral and peripheral proteins
- 5Integral proteins?Have hydrophobic and hydrophilic regions
-Most span the membrane completely
-Form ion channels, transporters, hormone receptors - 6Peripheral proteins?Attached to integral proteins on inner or outer surface of bilayer
-Aid in the support and function of membrane - 7Membrane CHOs?('glycocalyx')
Only on outer surface, bound to proteins or lipids
Used to 'anchor' cells together and for cell-to-cell recognition (e.g. egg and sperm) - 8Microvilli?Tiny fingerlike projections of the cell membrane (prominent in small intestine and kidney
- 9Fluid mosaic model of the cell membrane?The cell surface is constantly changing, as the phospholipids and some proteins are free to 'float' around
- 10Cytoplasm?All cellular material between the cell membrane and the nucleus
- 11Divisions of cytoplasm?Cytosol and organelles
- 12Cytosol?Gel-like intracellular fluid (ICF); mainly H2O
-Suspension of CHOs, proteins, lipids, and dissolved ions (thus is site of many chemical reactions)
-Higher [K+] and lower [Na+] than extracellular fluid (ECF) - 13Organelles?Specialized cellular compartments, each performs specific functions essential for life
- 14Non membranous organelles?In direct contact with cytosol!
- 15What are the different non-membranous organelles?Ribosomes, centrosomes, cytoskeleton
- 16Ribosomes?Sites of protein synthesis
- 17What do ribosomes contain and where can they be found?Contain rRNA and proteins, either floating free in the cytosol or attached to the ER
- 18Centrosomes?Dense area of cytoplasm
-Microtubule organizing center of the cell; organizes cytoskeleton
-Forms spindle apparatus for mitosis/meiosis
-The centrosome of most cells contains a pair of microtubules (centrioles); function uncertain although it it thought that centrioles may help direct movement of chromosomes during cell division - 19Cytoskeleton?Internal scaffolding of cell
-Composed of protein filaments
-Determines cell shape; provides strength and flexibility
-Important for cell division, and anchoring and movement of organelles and proteins (e.g. enzymes) - 20What is the cytoskeleton composed of?Microfilaments, intermediate filaments, microtubules
- 21Microfilaments?Made of actin subunits; involved in cell motility/shape changes
- 22Intermediate filaments?Tough protein filaments; structural integrity, composition is tissue specific
- 23Microtubules?Hollow tubes made of tubulin
-Forms centrioles, spindle, cilia, and flagella
-Move or secure organelles within the cytosol - 24Membranous organelles?All have bilayer membranes
-Separates organelles from the cytosol, allowing each to maintain its own unique internal environment - 25What are the different membranous organelles?Mitochondria, ER, golgi apparatus, lysosomes
- 26Mitochondria?'Power plants' of cells; major site of ATP synthesis
-Enclosed by two (smooth outer and folded inner) bilayer membranes
-Contain their own DNA (mtDNA), RNA, and proteins - 27Endoplasmic reticulum?Network of interconnected membrane channels
- 28Rough ER?Ribosomes attached, site of secretory, lysosomal, and membrane protein synthesis
- 29Smooth ER?No ribosomes, continuous with RER, functions vary with organ but include:
i) lipid and steroid hormone synthesis
ii) drug and toxin detoxification - 30Golgi apparatus?Stacks of membrane disks; sorts, modifies, packages, and delivers proteins and lipids to plasma membrane, lysosomes, or for secretion
- 31Lysosomes?Filled with digestive enzymes; breaks down bacteria, old organelles, and cells
- 32Nucleus?DNA containing control center of the cell, largest membranous organelle (cells may have 1+ nuclei)
- 33Parts of nucleus?Nuclear envelope, chromosomes, nucleolus
- 34Nuclear envelope?Has double (inner and outer) bilayer membranes
-Outer membrane continuous with ER, contains many pores - 35Nucleolus?Non-membranous, dense and dark staining bodies of DNA, RNA, and proteins within nucleus (1-2 per cell)
-Sites of ribosome production - 36Chromosomes/chromatids?Composed of DNA coiled around histone proteins, found in two forms
- 37Chromatin?When DNA strands not individually visible, most common state; present when cells are not dividing
- 38Chromosomes?Condensed, individually visible bar-like bodies found only during the process of cell division
-Either as single 'bars', or as a pair of sister chromatids - 39Somatic cells?All cells of body except those undergoing or resulting from meiosis
- 40How many chromosomes does the nuclei of a somatic cell have?46 chromosomes (23 from ovum, 23 from sperm) --> 23 pairs - 22 autosomal pairs and 1 sex pair
- 41Genes?'Functional' segments of DNA on along the chromosomes - each contain 'instructions' for the synthesis of proteins
- 42Homologous chromosomes?The fact that each autosomal chromosome pair is not identical, but equivalent: are highly similar in length and centromere position, and generally have genes for the same traits, at the same locus of both chromosomes, but... they may have different versions (alleles) of certain genes
- 43The cell life cycle?Series of changes that a cell goes through from the time it is formed until it reproduces
- 44Interphase?Period of normal cell activities and growth - DNA and histone proteins present as chromatin
- 453 divisions of interphase?G1 phase, S phase, G2 phase
- 46G1 phase?Rapid cell growth, increased protein synthesis
-Cells that no longer divide said to be in G0 phase - 47S (synthetic) phase?-DNA replicates, new histones made
-Resulting chromatin pairs (each strand termed a chromatid) held together by centromeres
-Kinetochores (protein) form on each centromere - 48Kinetochore protein?Site of attachment of spindle microtubules
- 49G2 phase?Additional growth and protein synthesis
-Production of enzymes, proteins needed for cell division
-Centrosome replication (initiated in G1) is completed - 50What stage of interphase are chromatids visible?None of them!
- 51How many hours is eachG1 - 8-10 hours
S - 6-8 hours
G2 - 4-6 hours - 52'M phase'?Essential for growth, tissue repair and reproduction. Involves: mitosis; division of nuclear material, and cytokinesis
- 53Mitosis?Production of two identical daughter cells (~1 hr)
-Occurs only in somatic cells - 54Prophase?-Chromatin condenses and coils, becoming visible
-Nuclear envelope fragments, nucleus disappears
-Centrosomes move to opposite sides (poles) of the cell
-Spindle apparatus grows out of centrosomes and attaches to kinetochore proteins on each centromere
-Spindles begin pulling chromosomes towards cell equator - 55Metaphase?All 46 double-stranded chromosomes line up on cell equator
- 56Anaphase?-Centromere splits, creating 92 single-stranded chromosomes
-Spindle pulls 46 chromosomes towards each pole
-Cytokinesis (division of cytoplasm) begins - 57Telophase?-Spindle apparatus disassembles
-Chromosomes uncoil and nucleolus reappears
-Nuclear envelope forms around each chromatid mass
-Cytokinesis ends - cells split - 58Meiosis?Production of gametes
-One diploid (2n) cell creates four genetically distinct haploid (1n) cells
Prior to meiosis, the events of interphase are unchanged - 59Meiosis; similarities to mitosis's?Prophase I & II: chromatin condenses into chromosomes, nuclear envelope and nucleoli disappear, spindle apparatus forms and joins to kinetochore
Anaphase I & II: cytokinesis begins
Telophase I & II: spindle disassembles, chromosomes to chromatin, nucleoli and nuclear envelope reappear, cytokinesis - 60Meiosis I name?Reduction division
- 61Unique to meiosis; prophase I?-Each homologous pair of chromosomes attaches together; forming a tetrad (23 tetrads formed)
-Crossing over can occur between chromatid strands within each homologous pair (increases diversity of offspring) - 62Metaphase I?23 tetrads line up at cell equator
- 63Anaphase I?-Tetrads split - each homologous chromosome pair, still connected by centromeres, pulled towards opposite poles (i.e. chromatids don't separate)
-Random segregation of mother and father chromosomes - 64Telophase I?Result: each 1n daughter cell lacks homologous chromosomes
- 65Interkinesis?An 'interphase-like' period, however, no DNA replication occurs during this period
- 66Meiosis II?Separation of chromatids, phases equivalent to those of mitosis
- 67Prophase II?Chromatin condenses; nuclear envelope/nucleoli disappear; spindle apparatus forms
- 68Metaphase II?The 23 double-stranded chromosomes of each daughter cell line up at the cell equator
- 69Anaphase II?-Centromeres split, creating 46 single-stranded chromosomes
-Spindle pulls 23 chromosomes towards each pole - 70Telophase II?-Centromeres split, creating 46 single-stranded chromosomes
-Spindle pulls 23 chromosomes towards each pole - 71Telophase II?Spindle disassembles, chromosomes uncoil, nuclear envelope and nucleolus reappear, cytokinesis
Result: four 1n gametes, each with 23 chromatin strands - 72Fertilization?Begins when haploid sperm penetrates 2^o oocyte, triggers completion of meiosis II in oocyte (becomes ovum), fusion of M and F pronuclei (1n) --> zygote (2n)
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- Anatomy Flashcards on Anatomy - The Cell, created by Emma Granger on 28/12/2016.
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- Emma Granger
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