BROCK BIOLOGY - CHAPTER 1

The Microbial World

Listeria monocytogenes

• soil organism

• infect other microbes such as amoebae

• have a unique ability to hijack cellular systems

microbiology

study of the dominant form of life on earth

microorganisms

• life forms too small to be seen by the naked eye

• live in microbial communities

microbial communities

a bacterial community with a diverse populations of microorganisms the live together in a shared environment and interact with one another

culture

collection of cells that have been grown in or on a nutrient medium

medium

a liquid or solid nutrient mixture that contains all of the nutrients required foro a microorganism to grow

growth

increase in cell number as a result of cell division

colony

visible mass or cluster of microorganisms growing on or within a solid culture medium

microbial cells

living compartments thet interact with their environment and with other cells in dynamic ways

viruses

not included because they are not cells

cytoplasmic membrane

a permeability barrier that separates the inside of the cell

cytoplasm

aqueous mixture of macromolecules

macromolecules

example is proteins, lipids, nucleic acids, and polysaccharides

ribosomes

responsible for protein synthesis

cell wall

a permeable structure located outside the membrane, it lends a structural strength to the cell, and much stronger than the cytoplasmic membrane

cell wall

found only in plant cell and not in animal cell

eukaryotic cell and prokaryotic cell

what are the cell types

eukaryotic cell

belong to the group of eukarya, where plants and animals are also found (such as algae, protozoa, and fungi). typically have organelles

organelles

assortment of membrane-enclosed cytoplasmic structure, this includes DNA, mitochondria, chloroplasts, and various other ____

prokaryotic cell

belong to the group of bacteria and archaea

prokaryotic cell

a cell that lacks nucleus and organelles, and appeared long before the evolution of other cell types

CCMNNRECG

answer the following

CCNCPR

answer the following

CCMNNEC

answer the following

CCNC

answer the following

DNA genome

all cells possess what?

gene

a segment of DNA that encodes a protein or an RNA molecule

genome

full set of genes in a cell

prokaryotic cell

typically closed circular chromosomes, but some are linear

eukaryotic cell

several linear moelcules, each formed into its own chromosomes

prokaryotic cell

aggregates in the cytoplasm to form the nuceoid

nucleoid

not enclosed by a membrane

prokaryotic cell

nucleoid is only found in what cell?

eukaryotic cell

enclosed within a membrane-bound nucleus

prokaryotic cell

contains plasmids

plasmids

a small distinct circles of DNA with non-essential specializeds genes like antibiotic resistance

prokaryotic cell

genome size is small and compact

eukaryotic cell

genome size is much larger and less streamlined example is a human cell

prokaryotic cell

contains between 500 and 10,000 genes encoded by 0.5 to 10 million base pairs

human cell

contains about 3 billion base pairs encoding 20,000-25,000 genes

metabolism

process by which cells acquire nutrients from the environment and transform into new cellular materials or waste products, using energy to support synthesis of new structures that lead to cell division

enzymes

a specialized proteins possessing catalytic activity that carry out the chemical reactions required to supply energy and perform biosynthesis inside the cell

DNA replication

a critical process of replicating the cells genome, which must happen before cell division take place

motility

the ability of many cells to sense and respond to envronmental changes, typically through self-propulsion, allowing them to physically relocate

differentiation

a process where some cells undergo modifications to form specialized cells tailored for survival, dispersal, or growth

intercellular communication

the ability of cells to respond to chemical signals from their environment, making them ‘aware’ of their surroundings so they can react accordingly

horizontal gene transfer

a process where many prokaryotic cells can exchnage genes directly with neighboring cells, regardless of whether the are of teh same species.

evolution

it occurs when genes within a population od cells change in their sequence and frequency over time, resulting in descent with modification.

structure, metabolism, growth, evolution

properties of all cells

differentiation, communication, motility, horizontal gene transfer

properties of some cells

morphology

the cells size and shape

micrometers

microscopic cells sizes is measured in?

0.5 to 10 micrometers

prokaryotes cell size is ranging from?

0.2 micrometers

size of smallest prokaryotes

mycoplasma pneumoniae

what is the smallest cell of prokaryotes

750 micrometer

largest size of prokaryotes

thiomargarita namibiensis

what is the largest prokaryotes

eukaryotes

generally larger on average, usually ranging from 5 to 100 micrometers

0.8 micrometers

smallest cell size of eukaryotes

smaller cells

they possess more surface area relative to their volume

smaller cells

they have higher surface-to-volume S/V ratio

4pier2

formula of surface area

4/3pier3

formula of volume

s/v ratio

it controls critical properties like growth rate and cell shape

growth rate

it depends heavily on how fast cells exchange nutrients and waste products with their environment

smaller cells

they can exchange nutrients and wastes more rapidly

coccus

spherical or ovoid shaped cells

rod or bacillus

cylindrically shaped cells

spirillum

spiral-shaped cells with rigid cell bodies

vibrio

slightly curved, comma-shaped cells

spirochete

spiral-shaped cells with flexible cell bodies

stalks or hyphae

used by some cells for attachment or to increase surface area

budding

a process that can result irregular and asymmetrical shaped cells during asymmetrical cell division

diplococci

cocci ocurring in pairs

streptococci

cocci forming long chains

tetrads or sarcinae

cocci ocurring in three-dimensional cubes

staphylococci

cocci ocurring in grapelike clusters

filamentous bacteria

long, thin, rod-shaped bacteria that divide terminally and form long filaments composed of many cells attached end to end

rods and cocci

very common shaped of cells

spiral, budding, and filamentous

less common shaped of cells