Cell Biochemistry Flashcards
complicated and highly organized
organisms
actively engaged in energy transformation
living system
flows from photosynthetic organisms through food chains to herbivores and on to carnivores at the apex of the food pyramid
solar energy
what is the bond formed by H, C, N, O
covalent bond
What is the most predominant biomolecule on Earth’s crust?
O (47%)
What are the 11 most predominant biomolecules on Earth’s crust (arranged from most to least abundant)
O, Si, Al, Fe, Ca, Na, K, Mg, Ti, H, C
What is the most predominant biomolecule in seawater?
Cl-
What are the 9 present biomolecules in seawater?
Cl-, Na+, Mg2+, So4 2-, Ca2+, K+, HCO3-, No3-, HPO4 2-
What is the most predominant biomolecule in the human body?
H
What are the 11 most abundant biomolecules in the human body?
H, O, C, N, Ca, P, Cl, K, S, Na, Mg
How many percent of the human body is hydrogen?
63%
How many percent of the human body is oxygen?
25.5%
How many percent of the human body is carbon?
9.5%
How many percent of the human body is nitrogen?
1.4%
How do inorganic precursors turn to cells?
inorganic precursors
metabolites
building blocks
macromolecules
supramolecular complexes
organelles
cells
_____ profoundly influence the structures and behaviors of all biological molecules
weak forces
What are the four weak forces?
Van de Waals Interactions
Hydrogen Bonds
Ionic Interactions
Hydrophobic Interactions
_____ is mediated by weak chemical forces
biomolecular recognition
_____ restrict organisms to a narrow range of environmental conditions
weak forces
How much time does it take for an electron transfer to occur?
10^-15 seconds
the period of evolution, from the first appearance of organisms to today
10^18 seconds
A single membraned-cell with no nucleus or organelles
prokaryotic cells
The light reactions in photosynthesis
Electron transfer
Who designed a thousand DNA segments and combined them to make a synthetic version of the genome of Mycobacterium mycoides, which, when transferred into the cytoplasm of a related species, produced new self-replicating cells?
J. Craig Venter
_____ opens the possibilities for creation of life forms for specific purposes – e.g., oil-eating bacteria that can synthesize molecules such as drugs
Venter’s work
Genetic elements enclosed in a protein coat
viruses
True or false. Viruses are free-living organisms and can reproduce only within cells.
False. Viruses are not free-living
What are the six major features of prokaryotic cells?
Cell wall, cell membrane, nuclear area or nucleoid, ribosomes, storage granules, cytosol
What is the function of the cell wall?
Mechanical support, shape, and protection against swelling in hypotonic media
What is the function of the cell membrane?
Highly selective permeability barrier that controls the entry of most substances into the cell
What is the function of the nuclear area/nucleoid?
Provides the operating instructions for the cell; the repository of the cell’s genetic information
What is the function of the ribosomes?
Sites of protein synthesis; mRNA binds to ribosomes then specifies the protein that is synthesized
What is the function of the storage granules?
Liberated and degraded by energy-yielding pathways when needed as metabolic fuel
What is the function of the cytosol?
Site of the intermediary metabolism, the interconnecting sets of chemical reactions by which cells generate energy and form the precursors for biosynthesis
What is the function of the extracellular matrix?
Complex coating that is cell specific and serves in cell-cell recognition and communication, creates cell adhesion, and provides a protective outer layer
What is the function of the nucleus?
Repository of genetic information encoded in DNA and organized into chromosomes
What is the function of the Endoplasmic Reticulum and ribosomes?
A labyrinth organelle where both membrane proteins and lipids are synthesized
What is the function of the Golgi apparatus?
Involved in packaging and processing of macromolecules for secretion and for delivery to other cellular compartments
What is the function of the mitochondria?
Power plants of eukaryotic cells where carbohydrates, fats, and amino acids are oxidized to CO2 and H2O
What is the function of the lysosomes?
Intracellular digestion of materials entering the cell via phagocytosis and pinocytosis and controlled degradation of cellular components
What is the function of the peroxisomes?
Act to oxidize certain nutrients, such as amino acids
What is the function of the cytoskeleton?
Determines the shape of the cell and gives it its ability to move; also mediates the internal movements that occur in the cytoplasm
What is the function of the chloroplasts?
Site of photosynthesis which light energy is converted into chemical energy in the form of ATP
What is the function of the mitochondria in plant cells?
Main source of energy generation in photosynthetic cells in the dark and in nonphotosynthetic cells under all conditions
What is the function of the vacuoles?
Transport and storage of nutrients and cellular waste products; allows the plant cell to grow dramatically in size with no increase in cytoplasmic volume
Covered with a flexible and sticky layer of complex carbohydrates, proteins, and lipids
Extracellular matrix
Roughly 50:50 lipid : protein as a 5-nm thick continuous sheet of lipid bilayer
Cell membrane (plasma membrane)
Separated by a double membrane, the nuclear envelope
Nucleus
Flattened sacs of internal membrane densely packed into helical arrays that extend throughout the cytoplasm of the cell and enclose a large interconnecting series of volumes called cisternae
Endoplasmic reticulum and ribosomes
An asymmetrical system of flattened membrane-bounded vesicles often stacked into a complex
Golgi apparatus
Surrounded by two membranes that differ markedly in their protein and lipid composition
Mitochondria
Vesicles 0.2-0.5 um in diameter, bounded by a single membrane; contain hydrolytic enzymes such as proteases and nucleases
Lysosomes
0.2-0.5 um single-membrane-bounded vesicles; contain a variety of exidative enzymes that use molecular oxygen
Peroxisomes
Composed of a network of protein filaments
Cytoskeleton
Have double-membrane envelope, an inner volume called stroma, and an internal membrane system rich in thylakoid membranes
Chloroplasts
The most obvious compartment in plant cells; very large vesicle enclosed by a single membrane called the tonoplast
Vacuole
Examples of biochemical reaction (2)
Glycolysis and Krebs cycle
4 biomolecules in organisms
Proteins
Nucleic acids
Carbohydrates
Lipids
The instructions for growth, development, and reproduction are encoded in each organism’s _____
nucleic acid
“before the nucleus”
Prokaryote
“true nucleus”
Eukaryote
Single-celled eukaryote (yeast)
Paramecium
True or false. Prokaryotes have nucleus
False. No definite nucleus; DNA present but not separate from rest of cell
Where is the enzyme for oxidation situated in prokaryotes
Plasma membrane (no mitochondria)
2 definite membranes of prokaryotes
-cells wall
-plasma membrane
The interior of the prokaryotes consists of _____ and ____
Cytoplasm, nucleoid region
Inclusion of cytoplasm of prokaryote
Ribosomes, various RNAs, proteins (enzymes), and small molecules
A single circular molecule of naked DNA
bacterial chromosome
Inclusions of eukaryotic cell
o Membrane-bound organelles
o Cytoplasmic membranes
o Other structures that lack surrounding membranes
Thin film of lipid and protein molecules held together by noncovalent interactions
Cell membrane
Functions of cell membrane
o Define and compartmentalize the cell
o Serve as scaffold for biochemical activities
o Provide selectively permeable barrier
o Provide means of transporting solutes
o Play a role in cell-to-cell communication and detection of external signals
- Principal feature that distinguishes eukaryotic from prokaryotic cells
Nucleus
Serves both as repository of genetic information and as the cell’s control center
Nucleus
Process involved in the nucleus (3)
DNA replication, transcription, and RNA processing
Plays a critical role in the generation of useful energy derived from the breakdown of lipids and carbohydrates
Mitochondria
True or false. Mitochondria possess its own DNA encoding for tRNA, rRNA, and some proteins
True
Most mitochondrial proteins are synthesized on _____
free ribosomes
Can harness solar energy to convert CO2 & H2O into carbohydrates
Chloroplast
True or false. Chloroplast need other organelles to synthesize their own amino acids, fatty acids, and lipid components of their own membranes
False. They synthesize their own
Where does the reduction of NO2- to NH3 occur?
Chloroplast
A network of membrane-enclosed tubules and sacs that extends from the nuclear membrane throughout the cytoplasm
ER
Largest organelle in the cell
ER
Consist of flattened sheets that is continuous to the outer nuclear membrane
RER
Characterized by the presence of ribosomes on the cytosolic side of the membrane
RER
Shape of SER
Tubular
Involve in lipid metabolism
SER
Cellular processes involving SER (2)
Drug detoxification
Carbohydrate metabolism and synthesis of neutral fats, phospholipids, and steroid
Consists of a series of flattened, membranous sacs (cisternae) involved in modifying, sorting, and packaging of macromolecules for secretion or for export to other organelles
Golgi complex
Golgi complex is formed by _____
fusion of vesicle that bud off the ER
Membrane-enclosed organelle the functions to degrade materials taken into the cell and to digest worn out cell components
Lysosome
Lysosome contains about _____ different hydrolytic enzymes that can _____
50, breakdown macromolecules
Small, membrane-enclosed organelles that contain enzymes in variety of metabolic reactions
Peroxisomes
Complex networks of protein filaments extending throughout the movement of the cell
Cytoskeleton
Three principal types of cytoskeleton
Microfilaments
Intermediate filaments
Microtubules
Also called the microtubule organizing center and it aids in cellular division
Centrosome
Functions as storage depots for nutrients wastes, and specialized materials such as pigments
Vacuole
