microbio lecture learning activity 1/chapter 3

Fimbriae

helps bacteria adhere to host tissue or other cells

Cytoplasm

site of metabolic reactions and molecule transport, contains enzymes, nutrients, and ribosomes.

Nucleoid

The genetic control center directs cell activities and replication.

Flagellum

propels the bacterium through liquid environments

Plasma membrane

Regulates the movement of substances in and out of the cell.

Cell wall

protection from osmotic lysis and mechanical stress;

Capsule

adds extra defense against phagocytosis.

Mutualism

both organisms benefit. (gut microbes)

Amensalism

One organism is harmed, and the other is unaffected. (Penicillium and bacteria)

Commensalism

One organism benefits, and the other is unaffected. (Staph infection)

Neutralism

Neither organism is affected by the interaction (vegetative bacteria and endospores)

Parasitism

One organism benefits, and the other is harmed. (viral infections)

Glycocalyx

Viscous and gelatinous, made of polysaccharide and/or polypeptide

Glycocalyx (capsule)

neatly organized and firmly attached

Glycocalyx (slime layer)

unorganized and loose

porins (proteins)

form channels through membrane

Gram-positive bacteria

produce exotoxins, high susceptibility to penicillin, disrupted by lysozyme.

Gram-negative bacteria

Produce endotoxins and exotoxins, low susceptibility to penicillin.

chromatophores

Photosynthetic pigments that are stored in membranes.

Plasmids

extrachromosomal genetic elements; carry non-crucial genes

Inclusions

reserve deposits within the cell, help regulate nutrients, many different kinds, some are only found in certain species

Endospores

Resting cells, produced when nutrients are depleted, are resistant to desiccation, heat, chemicals, and radiation, produced by bacillus and clostridium

sporulation

endospore formation

germination

endospore returns to vegetative state

Axial filaments/ endoflagella

anchored at one end of a cell

Peptidoglycan

repeating of disaccharides of NAG and NAM linked together by proteins

Porins (proteins)

Form channels through the membrane.

Cytoplasm

substance inside the plasma and outside the nucleus

Cytosol

fluid portion of cytoplasm

Cytoskeleton

made of microfilaments and intermediate filaments; gives shape and support.

Cytoplasmic streaming

movement of the cytoplasm throughout a cell.

Ribosomes

site of protein synthesis

Ribosomes (80s)

Consists of the large 60s subunit and the small 40s subunit.

Ribosomes (membrane-bound)

attached to endoplasmic reticulum

Ribosomes (70s)

In chloroplasts and mitochondria

Rough ER

studded with ribosomes, sites of protein synthesis

Smooth ER

No ribosomes; synthesizes cell membranes, fats, and hormones.

Golgi complex

Transport organelle, modifies proteins from the ER, transports modified proteins via secretory vesicles to the plasma membrane

Lysosomes

contained digestive enzymes

Vacuoles

bring food into cells; provide shape and storage

Peroxisomes

Produce H2O2, which breaks down molecules such as fatty acids

Centrosomes

network of protein fibers and centrioles forms the mitotic spindle; critical role in cell division

Mitochondria

Double membrane contains inner folds (cristae) and fluid (matrix). Involved in ATP production

Chloroplasts

location of photosynthesis, they have their own ribosomes and circular DNA, contains thylakoids that contain chlorophyl.

Endosymbiotic theory

Larger bacterial cells engulf smaller bacterial cells, developing the first eukaryotes.

Osmotic pressure

The pressure needed to stop the movement of water across the membrane