The Cell Flashcards
Living matter of any plant or animal is called _______.
Protoplasm
A single unit of protoplasm is called a ____.
Cell
Plants, animals, and humans consist of groups of __________ cells.
Interdependent
Interdependent cells _______ various functions.
Coordinate
Cells serving the same general function are called a _______.
Tissue
Pioneer of the cell
Robert Hook
Pioneer of microscopes
Leewenhoek
Pioneers of cell theory
Schwann and Schleiden
What are the components of the nucleus?
- Nucleo- or karyoplasm
- Chromosomes
Cytoplasm function and components
- Site of metabolic activities and specialized functions
- Organelles, Inclusions, Cytosol
Organelle description & classification
- Metabolically active, carry out specific functions
- Membranous or membrane limited
- Nonmembranous (includes cytoskeleton)
Cytoskeleton
Fibrillar components (microtubules, microfilaments, intermediate filaments, cytoplasmic matrix)
Inclusions
Metabolically inert, accumulate metabolic products (carbohydrates, proteins, lipids, crystals, pigments, secretory granules)
Cytosol (cytoplasmic matrix)
Fluid containing electrolytes (ions) and colloids
Plasma membrane
- Thin, selectively permeable
- Lipid bilayer
- Permeable to water and small uncharged molecules
- Special transport systems for charged particles
Two kinds of proteins in the plasma membrane
- Integral
- Peripheral
Integral Proteins
- Embedded within lipid bilayer
- Cell metabolism, regulation, integration
- Pumps, channels, receptors, linkers, enzymes, structural
Pumps
Transport certain ions such as Na+ and metabolic precursors
Channels
Passage of small ions
Receptors
For hormones, antibodies
Linkers
Anchor intracellular cytoskeleton
Enzymes
Variety of roles, Na+/K+ ATPase, ATP synthase, digestive
Structural
Form junctions with neighboring cells
Two populations of membrane bound endosomes
Early and late
Endosomes could be _____ or _____ and are involved in _________ pathways
Stable; transient; Endocytic
Early endosomes function to ______ and ______ proteins.
Sort; Recycle
Late endosomes become _______.
Lysosomes
Lysosomes are rich in _________ enzymes for intracellular digesting and are most active in ________ and ________.
Hydrolytic; Leukocytes; Phagocytes
Lysosomes have a unique _________ that is _______ to the hydrolytic digestion occurring in their lumen.
Membrane; resistant
Lysosomes are implicated in lysosomal ______ diseases, such as ________________.
Storage; Tay Sachs disease
The RER contains basophilic bodies called ______ bound to its cytosolic surface.
Ribosomes
The RER is typically composed of a network of _________ sacs called ________.
Flattened; Cisternae
The RER is _______ with the outer membrane of nuclear envelope which also bears ribosomes on its cytosolic surface.
Continuous
The cells that secrete large amount of proteins, such as _______, pancreas, or salivary glands have extensive ______.
Liver; RER
The function of the RER is _________ which after synthesis are transported to _________ by vesicles.
Protein synthesis; Golgi complex
Membranous elements of SER are typically _______.
Tubular
Tubules of SER form an interconnecting system of _________ curving through the cytoplasm.
Pipelines
SER is extensively developed in _________, ________, and _________.
Skeletal muscle; kindey tubules; steroid producing endocrine cells.
When homogenized, the SER fragments into smooth-surfaced vesicles (called _______) and RER into rough-surfaced vesicles.
Microsomes
SER is involved in systhesis of _______ including oils, phospholipids, and steroids.
Lipids
SER is involved in __________ and _________ of a variety of organic compounds using __________ enzymes.
Detoxification; Bioactivation; Microsomal
SER is involved in ________ (______) metabolism since it releases ___________ in liver cells.
Carbohydrate; Glycogen; Glucose-6-Phosphate
SER is involved in membrane _________ and _________.
Formation; Recycling
SER, as sarcoplasmic reticulum, sequesters and releases _____ in muscles and fibers.
Ca++
The Golgi Apparatus is a network of _______ with double membranes.
Tubules
The Golgi Apparatus is the site of _______, ______, _____, and _____ of synthesized products.
- Concentration
- Modification
- Packaging
- Shipping
The Golgi Apparatus consists of ______.
Cisternae
In the Golgi Apparatus, cis-face toward _____ and trans-face toward _____.
ER; PM
The Golgi Apparatus accomplishes transport by __________.
Membrane vesicles
The mitochondria are ______ of the cells, slender, rod like, double membranes.
Power houses
Inner membrane of the mitochondria extensively folded forming ______.
Cristae
The mitochondria has a ______ number of active cells generating ATP.
Greater
The three principal reaction cycles in the mitochondria
- Krebs cycle
- Electron transport chain
- B-oxidation of fatty acids
The mitochondria are ________, have their own DNA, and hence called semiautonomous.
Self duplicating
Peroxisomes are single membrane bounded organelles containing ________ including _____, _____, and _____.
Oxidative enzymes; Urate oxidase; D-amino acid oxidase; Catalase
Virtually all oxidative enzymes produce ______ as a by-product which is a toxic substance.
Hydrogen peroxide
Hydrogen peroxide is later degraded by ____ thus protecting the cells.
Catalases
A disorder involving non-functional peroxisomes results in ___________ which leads to early death.
Zellweger syndrome
Microtubules are hollow tubules, walls made of _______ (a polymer of _____)
Protofilaments; Tubulin
Function of Microtubules
Maintenance of cell shape
Microtubules originate or grow from ___________.
Microtubule-organizing center (MTOC)
Movement of intracellular organelles is generated by ___________ associated with microtubules.
Molecular motor proteins
Two families of molecular motor proteins
- Dyneins
- Kinesins
Dyneins
Cytoplasmic dyneins move organelles from cell periphery to MTOC
Kinesins
Move organelles from MTOC toward the cell periphery
Microfilaments include:
- Actin and myosin
- Ankyrin and Spectrin (RBC)
- Dystrophin (Muscle cells)
- Specialized in muscle cells - responsible for contractility of protoplasm
The diameter of intermediate filaments is in between that of ________ and _________.
Microtubules; microfilaments
Four major classes of intermediate filaments
- Keratins (cytokeratins): skin, hair
- Vimentins: mesodern derived cells
- Neurofilaments: neurons
- Lamins: nuclear envelope
Inclusions: Glycogen
- Major sites are liver and muscles
- Beta or single and Alpha or cluster particles
Inclusions: Lipids
- Spherical droplets of neutral lipids
- Histological perparations - lipids are removed - appear as clear vesicles
- Glyceraldehyde and osmium tetroxide preserve dark globules
- Adipose tissue are specialized for fat storage
Inclusions: Crystalline inclusions
-Found in certain cells such as Sertoli cells and interstitial cells of Leydig
Inclusions: Pigments
- Lipofuscin
- Hemosiderin
- Melanin
Lipofuscin
- Brown-gold pigment
- In cells of long life: cardiac, skeletal muscle and brain cells (neurons)
Hemosiderin
- By-product of hemoglobin degradation
- Brown pigments in spleen and phagocytes
- Iron-storage pigment
Melanin
- Responsible for skin and hair color
- Bound to a protein melanosomes
- A product of tyrosine
The cytoplasmic matrix also known as ____or ____ is a concentrated aqueous gel.
Ground substance; Cytosol
The cytoplasmic matrix contains molecules of different shapes and size, such as ____, ____, ____, and ____.
Electrolytes; Metabolites; RNA; Proteins
The cytoplasmic matrix is the ______ ____ component in most cells.
Largest single
The cytoplasmic matrix is the site of _________ process such as _______ and _________.
Physiological; Protein synthesis; Breakdown of nutrients
The cytoplasmic matrix is a complex three dimensional network of ____________ and ___________.
Microtrabecular strands; Cross-linkers
The nucleus is the _______ organelle, _______ located, and ______ or ______ shaped.
Largest; Centrally; Elliptical; Spherical
The nucleus stains ______ or ______ with _______.
Dark purple or blue; H&E
The nucleus contains irregular clumps in the ________ called _______ which contains genetic material DNA and RNA.
Nucleoplasm; Chromatin
The nuclear envelope is a double membrane with _____ made of proteins.
Pores
The nuclear envelope contains _____________ continuous with ER space.
Peritubular cisternae
The nuclear envelope breaks _______ cell division and forms again _____ division.
During; After
The chromatin consists of ____________ and _______.
Riobonucleoproteins; histones
Condensed chromatin & stainable
Heterochromatin
Dispersed chromatin & not stainable
Euchromatin
In dividing cells, ________ become visible and are _______.
Chromosomes; basophilic
Human somatic cells are _____ and have ____ chromosomes.
Diploid (2n); 46
Germ cells are ______ and have ____ chromosomes.
Haploid; 23
Abnormal cells exhibit _______.
Polyploidy
The nucleolus is _______, _____, and _____.
Retractile, Eccentric, Basophilic
The nucleolus forms ______________ and consists of various kinds of _____.
Nucleolus organizing region (NOR); RNA
Prophase
- Condensation of chromosomes
- Disappearance of nucleolus and nuclear envelope
- Formation of spindle
- Chromosomes with sister chromatids migrate toward center of spindle
Metaphase
- Centromeres align in center of spindle (equatorial plate)
- Each chromatid attached to different poles
- Centromere duplicated
Anaphase
- Chromosomes migrate toward poles
- Sister chromatids separate
- Cytokinesis begins
Telophase
- Condensation of chromosomes
- Nucleolus and nuclear membrane reappear
Meiosis is a form of _____ division of fundamental importance among sexually reproducing organisms.
Nuclear
Meiosis occurs in ________ with diploid (2n) chromosomes.
Eukaryotes
Two chromosomes of each diploid cell are called _________ chromosomes.
Homologous
Humans have ____ or ____ pairs of chromosomes.
46; 23
46 chromosomes of a ______ contain 23 from sperm and 23 from ova.
Zygote
Once zygote is formed, it _______ for several generations to become an adult organism.
Multiplies
_____ and ____ are called haploid cells because they have only one number of the homologous pair of chromosomes.
Sperm; Ova
Prophase I
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis
Leptotene
- Chromosomes condense
- Sister chromatids visible
Zygotene
- Homologous chromosomes aligned together
- Synapsis and tetrad formation
Pachytene
-Chromatids continue to condense
Diplotene
-Separation of paired homologous chromosomes
Diakinesis
- Condensation complete
- Prophase I ends
Metaphase I
- Spindle develops
- Chromosomes align at equatorial plate
Anaphase I
-Homologous chromosomes (not sister chromatids) separate
Telophase I
-First meiotic division is completed with complete separation of homologous chromosomes
Interphase
-A short recess between telophase and prophase II
Meiotic Division II
- Events similar to mitosis
- Include all four phases prophase, metaphase, anaphase, and telophase II
Cell Locomotion
- Ameboid movement of leukocytes; in cells in close contact; villi and microvilli are involved
- Cell movements may be random or directional; directional movement is called chemotaxis
Cell death
- Necrosis
- Apoptosis
- Normal cell life span is from a few days to 80 years or more
Necrosis
Mechanical injury, toxins, and anoxia
Apoptosis
Active and programmed cell death; environment, developmental history or genome
