BIOCHEM WEEK 1 Flashcards
• Basic unit of life simplest collection of matter that can live
Cell
(t or f)
• All living organisms are made up of cells
• Unicellular vs
Multicellular
• Prokaryotic vs
Eukaryotic
true
viewed thin samples of cork under a compound light microscope
Robert Hooke (1665)
first to observe microorganisms
Anton Van Leeuwenhoek (1674)
cell theory
Matthias Schleiden & Theodor Schwann (1839)
theory of biogenesis
Rudolf Virchow (1858)
T OR F
1. The cell is the basic structural and functional unit of all living organisms
2. All organisms are made up of one or more cells
3. Cells arise from preexisting cells
TRUUUU
Size • 0.5-5um
Nucleus • No nuclear membrane • Nucleoid region in the Cytosol
Genome • Circular DNA complexed with RNA
Membrane-bound organelles
• Absent
Site of energy generation
• Cell membrane
Cell division • Binary fission
PROKARYOTES
Size • >10 um
Nucleus • Membrane-bound nucleus
Genome • Linear DNA complexed with histones & proteins
Membrane-bound organelles • Present
Site of energy generation • Mitochondria
Cell division • Mitosis and Meiosis
EUKARYOTES
• Envelopes cell contents; serves as the boundary and supports its structure
• Regulates movement of material into and out of the cell
• Plays a role in cellular communication
Plasma Membrane
• Cell membrane, plasmalemma
• Gelatinous substance that fills the inside of the cell
• Enclosed by the plasma membrane
• Located external to the nuclear membrane
Cytoplasm
substance in which the organelles are suspended
Cytosol
• Provides structural support to cells
• Assist with cell motility and movement of materials throughout the cell
Cytoskeleton
• Microtubules
• Microfilaments
• Intermediate
filaments
Cytoskeleton
• Powerhouse of the cell - site of energy production in the form ofATP
• Double-membrane bound organelle
• Contains its own DNA
Mitochondria
• Site of protein synthesis
• 2 subunits
• large
• small
Ribosomes
• convoluted membranous network of intercommunicating channels called cisterns
• ROUGH
• Modifies,
transports, and
stores proteins
• SMOOTH
• Detoxification
• Lipid biosynthesis
Endoplasmic Reticulum
• Packaging center
• completes
modifications of proteins produced in the RER
• packages and addresses proteins made by the RER to their proper destinations
Golgi Apparatus
• Spherical, membrane-bound organelles
• Transport of cellular material
• Produced by the cell membrane
Vesicles
• Spherical, membrane-bound organelles
• Suicidal bags
• Contains enzymes
for digestion
• Produced by the
Golgi Apparatus
Lysosomes
• Spherical, membrane-bound organelles
• beta oxidation of lipids
• detoxification of harmful substances
• Formed by budding
from the ER
Peroxisome
houses the genetic material (DNA) of the cell for directing protein synthesis
Nucleus
consists of RNA and protein for ribosome assembly
Nucleolus
boundary between cytoplasm and nuclear contents
Nuclear envelope
PASSIVE TRANSPORT
• CARRIER PROTEINS facilitate movement of SOLUTES across a membrane
• from high to low concentration of solutes
(DOWNHILL / ALONG the concentration gradient)
• DoesNOTrequire
energy
Facilitated Diffusion
PASSIVE TRANSPORT
• movement of WATER across a semipermeable membrane
• from low to high concentration of solutes
• DoesNOTrequire energy
OSMOSIS
• PROTEIN PUMPS facilitate movement of SOLUTES across a semipermeable membrane
• from low to high concentration of solutes
(UPHILL / AGAINST the concentration gradient)
• REQUIRES energy
ACTIVE TRANSPORT
• Transport of materials across the cell membrane through vesicles that are formed or lost as material is brought into or out of a cell
VESICULAR TRANSPORT
VESICULAR TRANSPORT
• bulk movement of substances
INTO the cell by vesicles forming
at the plasma membrane
ENDOCYTOSIS
VESICULAR TRANSPORT
• Bulk movement of substance
OUT OF the cell by fusion of secretory vesicles with the plasma membrane
EXOCYTOSIS
ENDOCYTOSIS
Cell surface extends, forming pseudopodia that engulf particles that are internalized into a vacuole
White blood cell engulfing a bacterium
Phagocytosis
ENDOCYTOSIS
Cell membrane invaginates to form a pit containing extracellular fluid; the pit pinches off & forms a vesicle
Reabsorption of small proteins in the kidney
Pinocytosis
ENDOCYTOSIS
Ligands first bind to receptors on the plasma membrane, triggering the uptake of the receptor and bound substance
Uptake of cholesterol into cells
Receptor-mediated endocytosis
Phases of the Cell Cycle
• G1
•S
• G2
Interphase
Phases of the Cell Cycle
• Prophase
• Metaphase
• Anaphase
• Telophase
M Phase
Interphase
• cells accumulate needed
enzymes and nucleotides needed for DNA replication
G1
Interphase
• DNA replication
S
Interphase
• Cells grow in preparation for
mitosis
G2
• Chromosomes condense and become visible
• Centrosomes move toward opposite poles
• Spindle fibers emerge from centrosomes
• Nuclear envelope breaks down
PROPHASE
• Chromosomes line up at the
metaphase plate
• Each sister
chromatid is attached to a spindle fiber originating from opposite poles
METAPHASE
• Centromeres split in two
• Sister chromatids are pulled toward opposite poles
• Certain spindle fibers begin to elongate the cell
ANAPHASE
• Chromosomes arrive at opposite poles and begin to decondense
• Nuclear envelope material surrounds each set of chromosomes
• The mitotic spindle breaks down
• Spindle fibers continue to push apart
TELOPHASE
• Animal Cells:
A cleavage furrow separates the daughter cells
• Plant Cells:
A cell plate (new cell wall precursor) grows to separate the daughter cells
CYTOKINESIS
