Cells Flashcards
the basic unit of structure & function because it demonstrates all qualities of life processes
Cells
They invented lens (Lt. lentils)
Zaccharias & Hans Janssen (1590)
Father of Microscopy
Anton van Leeuwenhooke (1632)
He discovered cells (Micrographia)
Robert Hooke (1665)
a German botanist and co-founder of the cell theory
- “All plants are made of cells.”
Matthias Jakob Schleiden(1839)
a German zoologist and co-founder of the cell theory
- “All animals are made of cells.”
Theodor Schwann (1839)
a German physician and co-founder of the cell theory
- proposed biogenesis stated that all living cells arise from pre-existing living cells, that there is no spontaneous creation of cells from nonliving matter.
Rudolf Virchow(1858)
Modern Cell Theory:
- Cells make up all life.
- Cells are functional and structural units.
- Cells are formed by division.
- Cells contain hereditary information.
- Cells are chemically the same
Energy flow occurs within cells
cell wall
- Robert Hooke (1665)
- present in plant cells only
functions:
1. protects the plant cells
2. maintain its shape
3. prevents excessive uptake of water
cell membrane
- C. Naegeli and C. Cramer (1855)
- Present both in plant and animal cell
functions:
1. Covers and protect the cell
2. Facilitate substance transport
3. Maintain the shape of the cell
Protoplasm
- Johann Evangelist Purkinje (1839)
- Present both in plant and animal cell
functions:
1. Contains the endomembrane system that regulates protein traffic & performs metabolic functions
Nucleus
- Robert Brown 1833
- information and control center of the cell
Functions:
1. Houses the genetic information
Parts:
1. Nuclear Envelope -2 layers with pore complexes
2. Chromosomes – discrete unit of DNA
3. Nucleolus – synthesize rRNA
part of nucleus: 2 layers with pore complexes
nuclear envelope
part of nucleus: discrete unit of DNA
chromosomes
part of nucleus: synthesize rRNA
Nucleolus
Endoplasmic Reticulum
- Biosynthetic Highway
- Albert Claude (1945)
functions:
1. Transports protein to other parts of the cell
type of endoplasmic reticulum that synthesize lipids, store Ca+ & detoxify poison
Smooth ER
type of endoplasmic reticulum that makes secretory protein, membrane factory & synthesizes phospholipid
Rough ER
golgi apparatus
- Camillo Golgi (1898)
- Shipping & Receiving Center
Function:
1. Modifies & packages proteins
parts of golgi apparatus:
1. Cis Face
2. Trans Face
part of golgi apparatus that receive proteins from ER
Cis Face
part of golgi apparatus that modifies, packages & transport proteins
Trans Face
mitochondria
- Carl Benda (1898)
- Powerhouse of a cell
- Semi-autonomous
Function:
1. For cellular respiration that produces ATP
ribosomes
- George Palade (mid 1950s)
- Protein Factory
Function:
1. Synthesizes proteins
types:
1. Free Ribosomes
2. Bound Ribosomes
type of ribosomes that are suspended in the cytoplasm
Free Ribosomes
type of ribosomes that are attached to ER & n. envelope
Bound Ribosomes
lysosomes
- Christian de Duve (1917)
- Digestive Compartment
Functions:
1. Contains hydrolytic enzyme that digests excess or worn-out organelles
cell repair
Autophagy
phagein (to eat) & kytos (vessel)
Phagocytosis
cell destruction
Autodigestion
peroxisome
- J. Rhodin (1954)
- Oxidation
Function:
1. Converts fatty acids to smaller substances
2. produces hydrogen peroxide (H2O2) as a by-product
cytoskeleton
Nikolai Koltsov (1903)
Functions:
1. Responsible for cell motility
2. maintain shape
3. gives support
4. regulates biochemical activities
types of cytoskeleton:
- Microtubules
- Intermediate Filament
- Microfilament
Chloroplasts
- Konstantin Mereschowski (1905)
- Capture Light Energy
Function:
1. Contain the green pigment, chlorophyll, which captures light necessary for photosynthesis
Contents:
1. thylakoids
2. granum
3. stroma
contents of chloroplasts: membranous system in the form of flattened, interconnected sacs
thylakoids
contents of chloroplasts: stacks of thylakoid
granum
contents of chloroplasts: fluid outside the thylakoids
stroma
vacuoles
- Anton van Leeuwenhoek (1676)
- Diverse Membrane Compartments
Functions:
Holds organic and inorganic compounds
Types:
1. Food vacuoles
2. Contractile vacuoles
3. Central vacuoles
type of vacuoles: formed by phagocytosis
Food vacuoles
type of vacuoles: pumps excess water out of the cell
Contractile vacoules
type of vacuoles; (plant cell only) its membrane is selective in transporting solutes
Central vacuoles
Provides channel between adjacent cells and form seals to prevent leakage of ECF
INTERCELLULAR JUNCTIONS
- Marilyn Farquhar and George Palade (1963)
types of intercellular junctions:
- Plasmodesmata (Plant cells)
- Tight Junctions (Animal cells)
- Desmomes/Anchoring Junction(Animal cells)
- Gap Junctions/Communicating Junction (Animal cells)
types of cells:
- prokaryotic cells
- eukaryotic cells
It has a centromere in the center, such that both sections are equal length.
Metacentric Chromosomes
It has a centromere slightly offset from the center leading to a slight asymmetry in the length of the two sections.
Submetacentric Chromosomes
It has a centromere which is severely offset from the center leading to one very long and one very short section.
Acrocentric Chromosomes
It has a centromere at the very end of the chromosome.
Telocentric Chromosomes
division of the nucleus to form 2 genetically identical daughter nucleus with diploid number of chromosomes
Mitosis
The Key Roles of Cell Division
- For unicellular organisms’ reproduction = binary fission
- For multicellular organisms to grow & develop
- For cell renewal and repair
INTERPHASE
- Nuclear envelope is intact
- Chromosomes duplicate
- Nucleolus still present
- Centrioles duplicate
The 4 Mitosis Phases:
- Prophase
- Metaphase
- Anaphase
- Telophase
- Centrioles move to opposite poles & form mitotic spindle
- Chromosomes condense & form sister chromatids
- Nuclear envelope starts to fragment
- Nucleolus absent
PROPHASE
- Kinetochore microtubules attach at the kinetochore
- Nuclear envelope is absent
- Sister chromatids align at the metaphase plate
- Centrioles at opposite poles
METAPHASE
- Cohesion dissolved causing sister chromatids to part
- Kinetochore microtubules pull chromosome strands to the opposite poles
ANAPHASE
- Cytokinesis begins
- Nucleolus reforming
- Nuclear envelope starts to form
- Chromosomes less dense
TELOPHASE
division of the nucleus to form 4 genetically unidentical daughter nucleus with haploid number of chromosomes
Meiosis
Separates homologous chromosomes
Meiosis I
Separates sister chromatids
Meiosis II
- Centrioles move to opposite poles & form meiotic spindle
- Nucleolus absent
- Chromosomes condense (Synapsis occurs and Crossing-Over occurs)
- Nuclear envelope starts to fragment
PROPHASE I
Chromosomes appeared w/in the nuclear envelope but are NOT yet fully condensed (bouquet stage)
Leptotene
Synapsis occurs wherein homologs begin to unite by coming into approximate alignment
Zygotene
2 sister chromatids of each chromosome separate from each other making them look thicker
Pachytene
Fused non-sister chromatids begin to separate from each other by the chiasma (pl. chiasmata) movement toward the ends of the chromatids. This process of sliding toward the ends is known as terminalization.
Diplotene
Chromosomes coil tightly & so becomes shorter & thicker
Diakinesis
a process during prophase I, wherein replicated homologs pair up & become physically connected along their lengths by a zipper like protein structure, the synaptonemal complex
synapsis
genetic rearrangement between non-sister chromatids
crossing over
the physical manipulation of crossing over
chiasmata
