Chapter 7 Flashcards
What is the process by which chemical substances (nutrients) are acquired by the surrounding environment and used in cellular activities (metabolism and growth)?
microbial nutrition
What are some essential nutrients?
macro-nutrients and micro-nutrients
Which bacteria can assemble molecules from scratch?
E.coli
What’s the average percentage of water that cells contain?
70%
What is the most prevalent macromolecule?
proteins, followed by nucleic acids, carbohydrates and lipids
97% of the dry cell weight is composed of which organic compounds?
CHNOPS
What are heterotrophs?
organisms that obtain carbon in an organic form
What are autotrophs?
organisms that obtain carbon from CO2 (inorganic gas) that is present as 0.35% in air
What nitrogen fixing bacteria reduces molecular nitrogen into ammonia?
Rhizobium
What percentage of nitrogen is molecular or in the air?
79%
What percentage of oxygen is in the air?
20%
What is a major component of macromolecules and water?
oxygen
What is essential for metabolism of many organisms?
oxygen
What element maintains pH level in solutions?
hydrogen
What element is a prime force in redox reactions in respiration of cells?
hydrogen
What bacteria concentrates and stores phosphate in metachromatic granules?
Corynebacterium diphteriae
In what two amino acids is sulfur found?
cysteine and methionine
Which amino acid helps determine shape and structural stability of proteins by forming unique linkages called disulfide bonds?
cysteine
What is sodium essential for?
cell transport
What is the role of potassium in a cell?
for protein synthesis and membrane function
What mineral source is a stabilizer of cell wall and structure of endospores?
calcium
What mineral is a component of chlorophyll and a stabilizer of membranes and ribosomes?
magnesium
What is iron in cytochrome proteins used for?
cell respiration