Molecular Biology (Prelims) - Cells and Cell Reproduction WIP

not yet finished

structural and functional units of all living organisms

Cell

What part of a cell?
periphery of the cell, separating its contents from the surroundings

Plasma membrane

What part of a cell?
Composed of lipid and protein molecules that form a thin, tough, pliable, hydrophobic barrier around the cell

Plasma membrane

What part of a cell?
Barrier to the free passage of inorganic ions and most other charged/polar compounds

Plasma membrane

What part of a cell?
Transport proteins, Receptor proteins, and membrane enzymes

Plasma membrane

What part of a cell?
Not covalently linked therefore flexible and allows change of shape and size of the cell

Plasma membrane

What part of a cell?
Fission occurs without loss of membrane integrity

Plasma membrane

What part of a cell?
internal volume enclosed by the plasma membrane

Cytoplasm

What part of a cell?
Aqueous solution in the cytoplasm

Cytosol

What part of a cell?
Particulate components, membranous organelles examples

mitochondria and chloroplasts

What part of a cell?
Particulate components, supramolecular structures (site of protein synthesis and degradation)

ribosomes and proteasomes

What part of a cell?
contains Genome- complete set of genes, DNA

Nucleoid/Nucleus

What part of a cell?
eukaryotes ‘ double membrane

Nuclear envelope

What limits the dimensions of a cell

Lower limit and Upper limit

minimum number of each type of biomolecule required by the cell. Too little space for everything vital to occupy

Lower limit

Lower limit:
Smallest cells like mycoplasmas are about ___ nm in diabetes and have a volume of ___ mL

300 nm; 10-14 mL

Lower limit:

the size of a bacterial ribosome is __nm.

20 nm

rate of diffusion of solute molecules in aqueous systems

Upper limit

Surface-to-volume ratio increases with the decreasing cell size

Upper limit

Three Distinct Domains of Life

Bacteria, Archea, and Eukarya

What domain?
Inhabits soils, surface waters and the tissue of other living or decaying organisms

Bacteria

What domain?
Carl Woese (1980) inhabits extreme environments– salt lakes, hot springs, highly acidic bogs, and the ocean depths

Archaea

Who defined Archaea?

Carl Woese (1980)

What domain?
Evolved from the same branch that gave rise to the Archaea, more closely related to than bacteria

Eukarya

derived energy from the transfer of electrons from fuel molecules to oxygen within the cell

Aerobic habitats

derived energy from the transfer of electrons to Nitrate forming N2 , Sulfate forming H2S, or CO2 forming CH4

Anaerobic habitats

Anaerobes examples

Obligate anaerobes and Facultative anaerobes

What anaerobe?
die when exposed to oxygen

Obligate anaerobes

What anaerobe?
able to live with or without oxygen

Facultative anaerobes

Classifications of how they obtain the energy and carbon needed for synthesizing cellular material:

Phototrophs, Chemotrophs, Autotrophs

trophe (greek) means ____

nourishment

What classification of obtaining energy?
Trap and use sunlight

Phototrophs

Example of Phototrophs

cyanobacteria

What classification of obtaining energy?
○ Energy from oxidation of chemical fuel

○ inorganic - HSto S 0

Chemotrophs

Example of Chemotrophs

Humans

What classification of obtaining energy?
Synthesize all their biomolecules directly from CO2

Autotrophs

What classification of obtaining energy?
Some preformed organic nutrients made by other organisms

Heterotrophs

What membranous organelles in Eukaryotic Cell?
contains genes chromatin

Nucleus

What membranous organelles in Eukaryotic Cell?
segregates chromatin (DNA+protein) from cytoplasm

Nuclear envelope

Chromatin consists of

DNA+protein

What membranous organelles in Eukaryotic Cell?
site of ribosomal RNA synthesis

Nucleolus

What membranous organelles in Eukaryotic Cell?
most of the energy-extracting reactions of a cell

Mitochondria

What membranous organelles in Eukaryotic Cell?
synthesis and processing of lipids and membrane proteins

Endoplasmic reticulum and Golgi complexes

What membranous organelles in Eukaryotic Cell?
protein synthesis

ribosomes

Rough ER

What membranous organelles in Eukaryotic Cell?
drug metabolism and lipid synthesis

Smooth ER

What membranous organelles in Eukaryotic Cell?
transports lipids and proteins between ER, Golgi and plasma membrane

Transport vesicles

What membranous organelles in Eukaryotic Cell?
very long fatty chain fatty acids are oxidized

Peroxisomes

What membranous organelles in Eukaryotic Cell?
filled with digestive enzymes to degrade unneeded cellular debris (only in animal cells)

Lysosomes

What membranous organelles in Eukaryotic Cell?
supports the cell; aids in the movement of organelles

Cytoskeleton

In plant cells:
store large quantities of organic acids and metabolites; degrades and recycles macromolecules

Vacuoles

In plant cells:
sunlight drives synthesis of ATP in the process of photosynthesis occur; produces ATP and carbohydrates

Chloroplasts

In plant cells:
temporarily stores carbohydrate products of photosynthesis

Starch granule

In plant cells:
in the chloroplast that are the site of light-driven ATP synthesis

Thylakoid

In plant cells:
shape and rigidity; protects cell from osmotic swelling

Cell wall

In plant cells:
provides path between two plant cell

Plasmodesmata

In plant cells:
contains enzymes of the glyoxylate cycle

Glyoxysome

In plant cells nutrients are stored such as

starch and fat

Who discovered Cell Fractionation

Albrert Claude, Christian de Duve and George Palad

Methods for separating organelles from the cytosol and from each other

Cell Fractionation

Cell Fractionation:
Cells or tissues in solution are gently disrupted by ____ (ruptures the plasma membrane)

physical shear

Cell Fractionation:
Homogenate is then centrifuged resulting to ____ at different rates

sedimentation