Cell and Molecular Biology MIDTERM
properties of cell:
plasma membrane:
In vitro-outside the body
>outer boundary, encloses cell & support
In vivo-inside the body
>selective barrier
highly complex and organized
>communication
possess a genetic program and the means to use it
>separate intracellular substance from extracellular (intra:
capable of producing more of themselves.
inside; extra/inter: between)
acquire and utilize energy
Fluid Mosaic model
carry out a variety of chemical reactions
engage in mechanical activities > lipid bilayer
able to respond to stimuli > double layer of lipids with imbedded dispersal proteins.
capable of self-regulation > consist of phospholipids & cholesterol (20%)
phospo: hydrophobic (non-polar tails); hydrophilic (polar
Features held in common by the two types of cells heads)
cholesterol adds strength & flexibility
The plasma membrane has a similar construction across organisms.
Functions of Membrane Proteins
Genetic information is encoded in DNA using an identical genetic code.
Mechanisms for transcription and translation, including ribosomes, are > protein molecules “float” among phospholipid molecules
similar. Funtion:
Metabolic pathways like glycolysis and the TCA cycle are shared. 1. Marker Molecules- ID tags & cell surface recognition cell.
Apparatus for conserving chemical energy as ATP is similar (e.g., plasma 2. Transport Proteins- movement of molecules
membrane in prokaryotes and mitochondrial membrane in eukaryotes). 3. Receptor proteins- molecular triggers that set-off
Photosynthesis mechanisms are alike between cyanobacteria and green responses
plants. Movement through the Plasma Membrane
Mechanisms for synthesizing and inserting membrane proteins are
1. Diffusion
similar.
2. Osmosis
Proteasomes, protein-digesting structures, have similar construction in
3. Mediated Transport
archaebacteria and eukaryotes.
4. Vesicular Transport
1. Diffusion - movement of solute from an higher
Features of eukaryotic cells NOT found in prokaryotes concentration to lower concentration within a solvent.
Division of cells into nucleus and cytoplasm, separated by a nuclear equillibrium- uniform distribution of molecules.
envelope with complex pore structures. 2. osmosis- when a substance crosses a semipermeable
Complex chromosomes composed of DNA and associated proteins membrane in order to balance the concentrations of another
capable of compacting into mitotic structures. substance.
Presence of complex membranous cytoplasmic organelles, including osmotic pressure- force required to prevent the movement
ER, Golgi, lysosomes, endosomes, peroxisomes, and glyoxisomes. across a selectively permeable membrane.
Specialized organelles for aerobic respiration (mitochondria) and hypotoinic solution- low soluble concentration (burst).
photosynthesis (chloroplasts). isotonic- concentration of solute equal to that inside of
Complex cytoskeletal system, including microfilaments, intermediate cells (equal).
filaments, microtubules, and associated motor proteins. hypertonic- causes shrinkage. high concentration.
Presence of complex cilia and flagella. 3. Mediated Transport
Ability to ingest particulate material via phagocytosis. carrier proteins: bind to ions/ molecules & transport them.
Cellulose-containing cell walls in plants. 1. uniport- moves an ion/molecule down to its concentration
Cell division involving a microtubule-based mitotic spindle to separate gradient
chromosomes. 2. symport- moves 2 or more ions/molecules in the same
Diploidy, with two copies of each gene per cell (one from each parent). direction.
Presence of three RNA polymerases for synthesizing different RNA 3. antiport - moves 2 or more ions/molecules in the opposite
types. direction.
Sexual reproduction requiring meiosis and fertilization. cytoplasm
between plasma membrane & nucleus
model organisms half cytosol- consist of fluid part (site of chemical
E. coli-bacterium reactions) cytoskeleton & cytoplasmic
2 Saccharomyces cerevisiae- budding yeast > microtubules- support, aid in cell division, components of
Arabidopsis thaliana-flowering plant organelles. (25nm, tubulin sub units)
Caenorhabditis elegans-a - nematode >actin fillaments- support the plasma membrane, define the
Drosophila melangaster-a fruitfly shape of the cell. (8nm)
Mus musculus-mouse >intermediate fillaments- mechanical support (10nm)
half organelles
organelles, function of eukaryotic cell cytoplasmic inclusion-aggregates of chemicals other
produced by the cell or taken in (lipids, glycogen,
Function
hemoglobin, melanin)
1. Metabolize and release energy
cytoplasmic organelles- specialized subcellular structures
2. synthesize molecules
with specific function.
3. provide means of communication
membranous- mitochondria, perixosome, lysosome, e.r,
golgi apparatus.
non- membranous- cetrioles & ribosomes
, Nucleus
nuclear envelope consist of 2 separate membranes with nuclear
pores.
>encloses jelly-like nucleoplasm, contains essential sucks.
DNA found inside the nucleus
> hereditary material of cell & controls the activities.
> genetic library w/ blueprints for nearly all cell proteins.
> dictates the kinds & amounts of proteins to be synthesize.
> between cell division, DNA is organized as chromatin.
> during cell division, chromatin condenses to form chromosomes
consisting of 2 chromatids connected by chromosome.
Nucleoli - dark spherical bodies within the nucleus.
> consist of RNA & proteins
> produces ribosomal ribonucleic acid (rRNA) perixosome
> site of ribosomal subunit assembly
> membranous sacs containing oxidases and catalases
Ribosomes > breakdown of fatty acids, amino acids, and hydrogen
peroxide.
> sites of protein synthesis
> detoxify harmful substances
> free ribosomes are not attached to any organelles
> neutralize dangerous free radicals
>attached ribosomes are part of a network of membrane called the
free radicals- highly reactive chemicals with unpaired
rough e.r
electron.
Endoplasmic Reticulum- series of membrane forming sacs and
Mitochondrion
tubules that extend from the outer nuclear membrane into
cytoplasm. > major sites of the production of ATP (major energy sources)
Rough E.r via cellular respiration.
> studded with ribosomes > have smooth outer membrane and an inner membrane that
>major site of protein synthesis is infolded to produce cistae
Smooth E.r > contain own DNA, can produce some of their proteins, can
> does not have ribosomes attached replicate independently of the cell.
> major site of lipid and carbohydrate synthesis
centrioles- cylindrical organelles in the centrosome
1. liver: lipid and cholesterol metabolism, breakdown of glycogen & (triplets of microtubules)
along with the kidneys, detoxify drugs centrosome- specialized zone of cytoplasm
2. testes: synthesis of steroid-base hormones site of microtubule formation
3. intestine cells: absorption, synthesis & transport fats microtubules- called spindle fibers extend out in all
4. skeletal & cardiac muscle: storage and release of calcium directions from the centrosome
> involved in the separation of chromosomes during cell
Golgi apparatus- series of closely packed membranous sacs that division.
collect, package, and distribute proteins and lipids produced by e.r >from the bases of cillia and flagella
cilia- substance over the cells. a hair-like structure on
>secretory vesicles- transport material from the golgi apparatus to eukaryotic cells that helps with movement, fluid flow, and
exterior of the cell. mechanoreception.
flagella- propel sperm cells
microvilli- increase the surface area of cell and aids in
absorption and secretion.
Different types of biomolecules
Carbohydrates
> contain: carbon, hydrogen, oxygen 1:2:1 (C:H:O)
> major function: supply a source of cellular food
Examples:
1. monosaccharides- glucose and fructose
2. disaccharides- sucrose and lactose
3. polysaccharides- starch and glycogen
Lipids
lysosome - spherical membranous bag containing digestive enzymes. > Dissolve in nonpolar solvents, such as alcohol or acetone
> doesn’t dissolve in polar solvents, such as water
> digest ingested bacteria, virus, & toxins > Contain C, H, and O, the proportion of oxygen in lipids is less
> degrade non-functional organelles than in carbohydrates
> breakdown: glycogen & release thyroid hormone Examples:
non useful tissue 1. Fats or triglycerides: energy
bone to release calcium 2. Phospholipids: structural components of cell membranes
>secretory lysosome are found in white blood cells, imune cells, and 3. Eicosanoids: regulate physiological processes
melanocytes 4. Steroids: regulate physiological processes
properties of cell:
plasma membrane:
In vitro-outside the body
>outer boundary, encloses cell & support
In vivo-inside the body
>selective barrier
highly complex and organized
>communication
possess a genetic program and the means to use it
>separate intracellular substance from extracellular (intra:
capable of producing more of themselves.
inside; extra/inter: between)
acquire and utilize energy
Fluid Mosaic model
carry out a variety of chemical reactions
engage in mechanical activities > lipid bilayer
able to respond to stimuli > double layer of lipids with imbedded dispersal proteins.
capable of self-regulation > consist of phospholipids & cholesterol (20%)
phospo: hydrophobic (non-polar tails); hydrophilic (polar
Features held in common by the two types of cells heads)
cholesterol adds strength & flexibility
The plasma membrane has a similar construction across organisms.
Functions of Membrane Proteins
Genetic information is encoded in DNA using an identical genetic code.
Mechanisms for transcription and translation, including ribosomes, are > protein molecules “float” among phospholipid molecules
similar. Funtion:
Metabolic pathways like glycolysis and the TCA cycle are shared. 1. Marker Molecules- ID tags & cell surface recognition cell.
Apparatus for conserving chemical energy as ATP is similar (e.g., plasma 2. Transport Proteins- movement of molecules
membrane in prokaryotes and mitochondrial membrane in eukaryotes). 3. Receptor proteins- molecular triggers that set-off
Photosynthesis mechanisms are alike between cyanobacteria and green responses
plants. Movement through the Plasma Membrane
Mechanisms for synthesizing and inserting membrane proteins are
1. Diffusion
similar.
2. Osmosis
Proteasomes, protein-digesting structures, have similar construction in
3. Mediated Transport
archaebacteria and eukaryotes.
4. Vesicular Transport
1. Diffusion - movement of solute from an higher
Features of eukaryotic cells NOT found in prokaryotes concentration to lower concentration within a solvent.
Division of cells into nucleus and cytoplasm, separated by a nuclear equillibrium- uniform distribution of molecules.
envelope with complex pore structures. 2. osmosis- when a substance crosses a semipermeable
Complex chromosomes composed of DNA and associated proteins membrane in order to balance the concentrations of another
capable of compacting into mitotic structures. substance.
Presence of complex membranous cytoplasmic organelles, including osmotic pressure- force required to prevent the movement
ER, Golgi, lysosomes, endosomes, peroxisomes, and glyoxisomes. across a selectively permeable membrane.
Specialized organelles for aerobic respiration (mitochondria) and hypotoinic solution- low soluble concentration (burst).
photosynthesis (chloroplasts). isotonic- concentration of solute equal to that inside of
Complex cytoskeletal system, including microfilaments, intermediate cells (equal).
filaments, microtubules, and associated motor proteins. hypertonic- causes shrinkage. high concentration.
Presence of complex cilia and flagella. 3. Mediated Transport
Ability to ingest particulate material via phagocytosis. carrier proteins: bind to ions/ molecules & transport them.
Cellulose-containing cell walls in plants. 1. uniport- moves an ion/molecule down to its concentration
Cell division involving a microtubule-based mitotic spindle to separate gradient
chromosomes. 2. symport- moves 2 or more ions/molecules in the same
Diploidy, with two copies of each gene per cell (one from each parent). direction.
Presence of three RNA polymerases for synthesizing different RNA 3. antiport - moves 2 or more ions/molecules in the opposite
types. direction.
Sexual reproduction requiring meiosis and fertilization. cytoplasm
between plasma membrane & nucleus
model organisms half cytosol- consist of fluid part (site of chemical
E. coli-bacterium reactions) cytoskeleton & cytoplasmic
2 Saccharomyces cerevisiae- budding yeast > microtubules- support, aid in cell division, components of
Arabidopsis thaliana-flowering plant organelles. (25nm, tubulin sub units)
Caenorhabditis elegans-a - nematode >actin fillaments- support the plasma membrane, define the
Drosophila melangaster-a fruitfly shape of the cell. (8nm)
Mus musculus-mouse >intermediate fillaments- mechanical support (10nm)
half organelles
organelles, function of eukaryotic cell cytoplasmic inclusion-aggregates of chemicals other
produced by the cell or taken in (lipids, glycogen,
Function
hemoglobin, melanin)
1. Metabolize and release energy
cytoplasmic organelles- specialized subcellular structures
2. synthesize molecules
with specific function.
3. provide means of communication
membranous- mitochondria, perixosome, lysosome, e.r,
golgi apparatus.
non- membranous- cetrioles & ribosomes
, Nucleus
nuclear envelope consist of 2 separate membranes with nuclear
pores.
>encloses jelly-like nucleoplasm, contains essential sucks.
DNA found inside the nucleus
> hereditary material of cell & controls the activities.
> genetic library w/ blueprints for nearly all cell proteins.
> dictates the kinds & amounts of proteins to be synthesize.
> between cell division, DNA is organized as chromatin.
> during cell division, chromatin condenses to form chromosomes
consisting of 2 chromatids connected by chromosome.
Nucleoli - dark spherical bodies within the nucleus.
> consist of RNA & proteins
> produces ribosomal ribonucleic acid (rRNA) perixosome
> site of ribosomal subunit assembly
> membranous sacs containing oxidases and catalases
Ribosomes > breakdown of fatty acids, amino acids, and hydrogen
peroxide.
> sites of protein synthesis
> detoxify harmful substances
> free ribosomes are not attached to any organelles
> neutralize dangerous free radicals
>attached ribosomes are part of a network of membrane called the
free radicals- highly reactive chemicals with unpaired
rough e.r
electron.
Endoplasmic Reticulum- series of membrane forming sacs and
Mitochondrion
tubules that extend from the outer nuclear membrane into
cytoplasm. > major sites of the production of ATP (major energy sources)
Rough E.r via cellular respiration.
> studded with ribosomes > have smooth outer membrane and an inner membrane that
>major site of protein synthesis is infolded to produce cistae
Smooth E.r > contain own DNA, can produce some of their proteins, can
> does not have ribosomes attached replicate independently of the cell.
> major site of lipid and carbohydrate synthesis
centrioles- cylindrical organelles in the centrosome
1. liver: lipid and cholesterol metabolism, breakdown of glycogen & (triplets of microtubules)
along with the kidneys, detoxify drugs centrosome- specialized zone of cytoplasm
2. testes: synthesis of steroid-base hormones site of microtubule formation
3. intestine cells: absorption, synthesis & transport fats microtubules- called spindle fibers extend out in all
4. skeletal & cardiac muscle: storage and release of calcium directions from the centrosome
> involved in the separation of chromosomes during cell
Golgi apparatus- series of closely packed membranous sacs that division.
collect, package, and distribute proteins and lipids produced by e.r >from the bases of cillia and flagella
cilia- substance over the cells. a hair-like structure on
>secretory vesicles- transport material from the golgi apparatus to eukaryotic cells that helps with movement, fluid flow, and
exterior of the cell. mechanoreception.
flagella- propel sperm cells
microvilli- increase the surface area of cell and aids in
absorption and secretion.
Different types of biomolecules
Carbohydrates
> contain: carbon, hydrogen, oxygen 1:2:1 (C:H:O)
> major function: supply a source of cellular food
Examples:
1. monosaccharides- glucose and fructose
2. disaccharides- sucrose and lactose
3. polysaccharides- starch and glycogen
Lipids
lysosome - spherical membranous bag containing digestive enzymes. > Dissolve in nonpolar solvents, such as alcohol or acetone
> doesn’t dissolve in polar solvents, such as water
> digest ingested bacteria, virus, & toxins > Contain C, H, and O, the proportion of oxygen in lipids is less
> degrade non-functional organelles than in carbohydrates
> breakdown: glycogen & release thyroid hormone Examples:
non useful tissue 1. Fats or triglycerides: energy
bone to release calcium 2. Phospholipids: structural components of cell membranes
>secretory lysosome are found in white blood cells, imune cells, and 3. Eicosanoids: regulate physiological processes
melanocytes 4. Steroids: regulate physiological processes
