BIOL 207 Exam 2

macronutrients

required in large quantities and play important roles in cell structure and metabolism

micronutrients

involved in enzyme function and maintenance of protein structure

heterotroph

organism that must obtain carbon in organic form

autotroph

uses inorganic carbon dioxide

phototroph

photosynthesizes

chemotroph

gains energy from chemical compounds

obligate parastie

can’t live outside of human host

diffusion

movement of atoms/molecules from high to low density

osmosis

movement of water through membrane

active transport

against the diffusion gradient, involves membrane protein, expends ATP

endocytosis

cell encloses substance in membrane, forms vacuole and engulfs substance

phagocytosis

ingests whole cell/large solid matter

pinocytosis

ingests liquid

cardinal temperatures

range of temperatures for given microbial species

minimum temperature 

the lowest temperature at which an organism will grow 

maximum temperature

the highest temperature at which an organism will grow

optimum temperature

promotes the fastest rate of growth and metabolism

psychrophiles

optimum temp: >15 C

psychrotrophs

optimum temp: 15-30 C

mesophiles

optimum temp: 20-40 C majority of medically significant microorganisms

thermoduric

survive short exposure to high temperatures

thermophile

optimum temperature: 45-80 Ce

extreme thermophiles

optimum temperature: 80-121 C

obligate aerobes

can’t grow without oxygen

facultative aerobes

use oxygen when it’s present, but don’t require it

microaerophiles

require smaller amounts of oxygen than in the atmosphere

capnophiles

grow best in high carbon dioxide tension

acidophiles

grow best in acidic environments (pH <7)

alkalinophiles

organisms that thrive in alkaline (pH >7)

binary fission

a form of asexual reproduction in which one cell divides to form two identical cells 

generation time/doubling time

the time required for a complete fission cycle, from parent cell to two daughter cells

growth curve 

pattern of bacteria growth in a closed system

lag phase

flat, little growth

log phase 

the period of exponential growth of bacterial population

stationary phase

period of equilibrium; microbial deaths balance production of new cells

death phase

more cells dying than multiplying due to waste buildup

metabolism

all chemical and physical workings of a cell

anabolism

any process that results in synthesis of cell molecules and structure, requires input of energy

catabolism

breaking down molecules, releases energy

enzymes

catalysts for chemical reactions

substrate

acted on by enzymes

cofactors

support enzymes

aerobic respiration

relies on free oxygen as the final electron receptor

anaerobic respiration

uses oxidized compounds as final electron receptor

fermentation

incomplete oxidation of glucose

glycolysis

turns glucose into pyruvate

krebs cycle

transfers energy stored in acetyl CoA to NAD+ and FAD by reducing them, NADH and FADH2 carry electrons to ETC, 2 ATPs produced for each glucose molecule

phosphorylation

2 ATPs produced for each glucose molecule 

genetics

the study of heredity

genome

all of an organism’s genetic material

what are the macronutrients

carbon, hydrogen, and oxygenwha

t are the micronutrients

manganese, zinc, and nickel a 

a heterotroph is an organism that must obtain its carbon in

an organic form 

an autotroph is an organism that uses

inorganic CO2 as its carbon source

autotrophs are not

nutritionally dependent on other living things

obligate parasites are unable to 

grow outside of a living host 

the vast majority of microbes causing human disease are

chemoheterotrophs

what is diffusion

movement of atoms/molecules from an area of higher density or concentration to an area of lower density or concentration

osmosis is the diffusion of water through a 

selectively, differentially, or permeable membrane

phagocytosis ingest

whole cells or large solid matter

pinocytosis is the ingestion of

liquids such as oils or molecules in solution

the storage of psychrophiles at refrigerator temperature

incubates rather than inhibits them

what are able to grow at refrigerator temperatures and cause food-borne diseases

Staphylococcus aureus and listeria

what are the majority of medically significant microorganisms

mesophiles

human pathogens have optimal temperatures between

30 C and 40 C

thermoduric are common contaminants of

heated or pasteurized foods

examples of thermodurics are

spore formers such as Bacillus and Clostridium

thermophiles grow optimally at temperatures

greater than 45 C

extreme thermophiles grow between

80 C and 121 Cthe

the atmospheric gases that influence microbial growth are

O2 and CO2

what are the organisms that cannot grow without oxygen

obligate aerobes 

what does not require oxygen for metabolism, bu use it when it is present

facultative aerobes

what requires a small amount of oxygen in metabolism

microaerophiles

carbon dioxide is important in the initial isolation of the following organisms from clinical specimens 

Neisseria (gonorrhea, meningitis) and Streptococcus pneumoniae 

the majority of organisms live or grow in habitats between

pH 6 and 8

many molds and yeasts tolerate

acid and are the primary spoilage agents of pickled foods

what is the time required for a complete fission cycle, from parent cell to two daughter cells

generation/doubling time 

the length of the generation time is a measure of the

growth rate of an organism

a predictable pattern of a bacterial population growth in a closed system can be measured

growth curve

flat growth are cells not yet 

multiplying at their maximum rate 

what is a growth that increases geometrically

exponential growth (logarithmic or log) phase in

stationary growth phase, cell birth and cell death rates are

equal

microbes in teh exponential growth phase are more vulnerable to 

antimicrobial agents and heat

actively growing cells are more vulnerable to

conditions that disrupt cell metabolism and binary fission

a person actively shedding bacteria in the early and middle stages of infection is more likely to

spread it than a person in the later stages

anabolism is nay process that results in 

synthesis of cell molecules and structures 

anabolism requires the input of

energy

what breaks the bonds of larger molecules into smaller molecules and releases energy

catabolism

enzymes are 

catalysts that increase the rate of chemical reactions without becoming part of the products or being consumed in the reaction w

hat are reactant molecules acted on by an enzyme

substrates wh

at speeds up the rate of reactions

enzymes

enzymes are much larger in size than

substrates 

enzymes have unique

active sites on teh enzyme that fits only the substrate

what are some trace elements that function as cofactors for enzymes

iron, copper, magnesium, manganese, zinc, cobalt, selenium

cofactors help bring th

active site and substrate close together 

what are organic compounds that work in conjunction with an apeoenzyme

coenzymes 

coenzymes carry and transfer

hydrogen atoms, electrons, carbon dioxide, and amino groups

many coenzymes are derived from

vitamins

a temporary enzyme-substrate union must occur at the 

active site 

ATP utilization and replenishment is an 

ongoing cycle