cell structure and metabolism

Question 1

what is the diffrence between prokarayotes and eurkoyte

Answer 1

prokaryotes - singnificantly smaller and have a nucleoid they do not have organelles and the ribosome size 70s
Eukaryotes are larger and possess a nucleus as well as containing organelles, the ribosomes are size 80s

Question 2

describe the defineing traits of bacteria

Answer 2

Bacteria - The chromosome and ribosomes are loose in the cytoplasm which is encased in a plasma membrane, followed by a cell wall then finally externally there is a capsule which often has many pili and flagella for movement.

Question 3

list the shapes of bacteria

Answer 3

cocci - diplo, strepto, tetrad, sarcine, staphylo
Bacilli - diplo, trepto,cocco
Spiral - vibrio, sprillium, spirochete

Question 4

Describe the structure and function of the glycocalyx

Answer 4

A polysaccharide outside the cell wall, of which is used to stick to surfaces and prevents phagocytosis invading the immune system macrophages. The substance is made inside the cell and secreted externally, this is referred to as the capsule

Question 5

describe flagella

Answer 5

used for motility, they are connected to the body by the basal body, the flagella is formed by chains of proteins which rotate with the basal body. This allows them to swim. There are two types Trichous - hairlike and Atrichous - without flagella. Naming components like peri, mono, a, amphi and lopho are used.

Question 6

describe axial fillaments

Answer 6

also called endoflagella - are inside the spirochetes, they run inside the cell and rotate, much similar to a corkscrew.

Question 7

descirbe Fimbriae

Answer 7

small projections of which reach out to nearby bacteria of which facilitate attachment to surface or cells.

Question 8

describe pili

Answer 8

composed of protein, they are tubes used for sex, DNA is passed through the tube into the other bacteria. This is the reason for antibiotic resistance.

Question 9

Describe bacterial motility and there two types

Answer 9

Motility is the movement and behavioural description of the bacteria, they are described as two types, chemotaxis (reacts to chemicals) and phototaxis (reacts to light).

Question 10

what is the diffrent types of movement for prokayote and eukaryote flagells

Answer 10

Prokaryote - the flagella rotates and is composed of flagellin.
Eukaryotic - flagella beats (like a whip/wave) and is made from microtubules. Have many small fagella named cilia.

Question 11

Compare and contrast the cell walls of Gram+ with Gram- bacteria

Answer 11

Gram positive have a thick peptidoglycan with no outer membrane and poses Teichoic acid crosslinks in the peptidoglycan
Gram negative have a thin peptidoglycan with an outer membrane in between the membrane a periplasmic space is found. And the outer membrane contains lipopolysaccharide (LPS).

Question 14

descibe endosymbiotic theory

Answer 14

Lynn Marguilis proposed the endosymbiosis theory of evolution. It describes ancient eukaryotic cells engulfing or were invaded by prokaryotes of which we now know to be chloroplasts and mitochondria.

Question 15

what features of choloplasts and mitcochondira are shared with bacteria.

Answer 15

Circular DNA which allows replication, independent from host cell
Similar size and shape
Ribosomes are the same size and shape as bacterial ribosomes.
Divide by binary fission
Membrane thickness is the same.