Lecture 2a

Question 1

Elements common to all living cells

Answer 1

-Plasma membrane
-Cytoplasm
-Chromosome
-Ribosomes
-Cytoskeleton

Question 2

Plasma membrane

Answer 2

surrounds all cells, a bilayer made of phospholipid molecules with embedded protein
controls the flow of substances in and out of a cell

Question 3

what are the characteristics of a lipid bilayer

Answer 3

hydrophobic barrier to water-soluble substances
selected cells can penetrate cell membranes through transport channels
selective transport maintains the specialized internal environments required for life

Question 4

DNA

Answer 4

Genetic info of all cells
is hereditary
is located in the centre region (nucleus)
double helix bond formed by 2 complementary strands of nucleotides held together by hydrogen bonds

Question 5

RNA

Answer 5

messenger of DNA, nucleic acid present in all living cells, carries instructions from DNA to be passed down across the cell

Question 6

tRNA

Answer 6

a small RNA molecule that plays a key role in protein synthesis

Question 7

ribosomes

Answer 7

technically not a organelle; proteins + rRNA
its the sight of protein synthesis
MAKES PROTEIN

Question 8

Whats the difference of ribosomes in prokaryotic and eukaryotic cells

Answer 8

p= float around in cytosol
e=attatched to the nuclear envelope or too rough ER or floating in cytosol

Question 9

Cytoplasm

Answer 9

between the plasma membrane and the central region. holds the internal components of a cell together and protects them
includes the cytoskeleton and cytosol

Question 10

Cytoskeleton

Answer 10

Maintains cell shape and plays a key roll in cell division and chromosome seggregation

Question 11

Cytosol

Answer 11

the aqueous portion of the cytoplasm in an intact cell, containing water, dissolved ions and various molecules

Question 12

All organsims consist of one of two cell types

Answer 12

Prokaryotes and eukaryotes

Question 13

Prokaryotes Domains

Answer 13

Bacteria and Archaea

Question 14

Eukaryotes domains

Answer 14

Eukarya; Animals, plants, fungi

Question 15

Prokaryotes key charcteristics

Answer 15

Lack a nucleus; DNA is located in a region called the nucleoid.
No membrane-bound organelles.
Common shapes: spherical, rodlike, and spiral.
Typically have a single circular DNA molecule (prokaryotic chromosome).

Question 16

Prokaryotic cell structure

Answer 16

surrounded by a plasma membrane and often rigid cell wall
the outter layer can be a glycolax (loose slime layer or firm capsule
Contain ribosomesand may have structures like flagella for movement and pili for adhesion and mating.

Question 17

Relate plasmids and prokaryotic cells

Answer 17

Some contain extrachromosomal DNA (plasmids), which can carry genes for antibiotic resistance and can transfer between cells.

Question 18

Eukarya key charcteristics

Answer 18

Have a nucleus and cytoplasmic organelles enclosed within a plasma membrane.
More complex than prokaryotic cells, with a well-defined endomembrane system.

Question 19

Eukaryotic cell structure

Answer 19

Contain various organelles for specialized functions (e.g., mitochondria for cellular respiration).
Ribosomes can be free in the cytosol or attached to membranes.
A complex cytoskeleton supports cell structure and aids in transport and division.

Question 20

Key differences between eukaryotes and prokaryotes

Answer 20

Prokaryotes are simpler, lacking a nucleus and membrane-bound organelles, while eukaryotes are more complex, featuring compartmentalized structures and specialized functions.