Biomolecules and Cells Flashcards
More than 97% of the weight of most organisms consists of elements such as
H
O
C
N
S
P
What trace elements required for life as cofactors
Zn
Fe
Mn
Cu
Co
What are the four major types of biomolecules
Amino acids
Nucleotides
Simple sugars/ carbohydrates
fatty acids/ lipids
nitrogen-containing molecules that function primarily as the building blocks for proteins
amino acids
consist of a nitrogenous base, a five-membered sugar (ribose or deoxyribose), and one to three phosphate groups
nucleotides
the building blocks of nucleic acids
nucleotides
what is the difference between nucleotides and nucleosides
nucleotides contain a nitrogenous base, five-membered sugar (ribose or deoxyribose), and one to three phosphate groups
while
nucleosides contain a nitrogenous base and a sugar without the phosphate groups
the building blocks of nucleic acids
Nucleotides
formed only of carbon, oxygen, and hydrogen (with a 2:1 ratio of hydrogen to oxygen atoms)
carbohydrates/ simple sugar
the building block of carbohydrates
simple sugars
amphipathic molecules (polar and nonpolar chemical properties contained within the same molecule)
fatty acids/ lipids
made up of covalently linked amino acids in the form of polypeptides through peptide bonds
proteins
polynucleotides consist of covalently linked nucleotides through phosphodiester bonds
nucleic acids
polysaccharides by linking simple sugars through glycosidic bonds.
carbohydrates
A network of metabolic pathways consisting of linked biochemical reactions in which the product of one reaction is the reactant for another reaction.
metabolism
Three types of linked reactions
commonly found in metabolism
Linear metabolic pathway
Forked metabolic pathway
Cyclic metabolic pathway
each reaction generates only a single product, which is a reactant for the next reaction in the pathway.
Linear metabolic pathway
usually generate two products, each of which undergoes a different metabolic fate.
Forked metabolic pathway
contain several metabolites that regenerate during each turn of the cycle, serving as both reactants and products in every reaction.
Cyclic metabolic pathway
is the basic unit of life.
cell
single-celled organisms
prokaryotes
2 types of cells
prokaryotes
eukaryotes
prokaryotes are
- singled-celled organisms
- shapes: spherical (cocci), rodlike (bacilli), or helically coiled (spirilla)
- no defined membrane-bound nucleus
- have a nuclear region, which contains DNA, ribosomes (site of protein synthesis), and cell membrane.
- types: eubacteria and archaebacteria
eukaryotes are
- more complex organisms that can be multicellular or single-celled
- contains a membrane-bound nucleus and other subcellular organelles
- types: animal cells and plant cells
TRUE or FALSE
do prokaryotes and eukaryotes have nucleus?
FALSE
prokaryotes have no definite nucleus
TRUE or FALSE
In prokaryotes, DNA is present but not separate from the rest of the cell
TRUE
TRUE or FALSE
prokaryotes and eukaryotes have cell membranes AND RIBOSOMES
TRUE
TRUE or FALSE
prokaryotes and eukaryotes have mitochondria, ER, and chloroplasts
FALSE
Prokaryotes do not have mitochondria, ER, and chloroplasts
Photosynthesis in prokaryotes are localized in
chromatophores
most important eukaryotic organelle; a membrane-bound organelle that contains the cell’s genetic material (DNA) that provides the operating instructions for the cell.
nucleus
segregates chromatin (DNA + protein) from the cytoplasm
nuclear envelope
rich in ribosomal RNA and proteins to form ribosomes
nucleolus
consists of DNA compacted with nucleic acid binding proteins to minimize its size
chromosomes
site of ATP synthesis, thus the powerhouse of the cell; metabolic reactions occur involved in energy conversion and production of ATP; has its own DNA; site of fatty acid degradation and citric acid cycle
mitochondria
Tough, flexible lipid bilayer; a highly selective permeability barrier that regulates the movement of materials into and out of the cell; and contains membrane proteins that function in transport in signal reception and as enzymes; separate the cell from the environment.
cell/ plasma membrane
site of lipid synthesis and drug metabolism
Smooth ER
studded with ribosomes bound to the
Membrane; site of membrane and secretory protein biosynthesis and their post-translational modification.
Rough ER
membranous structure involved in protein translocation within the cell and in facilitating protein; packaging and processing of macromolecules for secretion and delivery to other cellular compartments.
Golgi apparatus
convert light energy into chemical energy; harvests sunlight, produces ATP and carbohydrates; site of photosynthesis; has its own DNA
chloroplasts
site of light-driven ATP synthesis
thylakoid
site of carbon dioxide fixation
stroma
membrane-enclosed sacs that degrade intracellular debris; responsible for the intracellular digestion of materials entering the cell via phagocytosis or pinocytosis; contains hydrolytic enzymes which work best at pH 5
lysosomes
sacs containing enzymes involved in the breakdown of amino acids and fatty acids forming hydrogen peroxide which is rapidly degraded by the peroxide-cleaving enzyme catalase to produce water and oxygen from hydrogen peroxide.
peroxisomes
a viscous fluid organelle that contains all other organelles
cytoplasm
provides mechanical support, shape and rigidity, and protection against osmotic swelling
cell wall
degrades and recycles macromolecules, stores metabolites
vacuoles
are large RNA-protein complexes that are the sites of protein synthesis in prokaryotic and eukaryotic cells; can also be found in the cytosol.
ribosomes
a network of intracellular filaments consisting of assemblies of proteins that support cells and aid in the movement of the cell.
cytoskeleton
are constructed of microtubules, cytoplasmic projections extending outside of the cell, usually used for movement.
cilia and flagella
are membrane-lined channels that traverse the walls between neighboring plant cells. Mostly contain a desmotubule, a central tube of endoplasmic reticulum (ER), that connects the ER of adjacent cells.
plasmodesma
