A2.2: Cell Structure

Question 1

Cell theory

Answer 1

1. All living things have cells, 2. The cell is the basic unit of life, 3. Cells come from preexisting cells

Question 2

Plasma membrane

Answer 2

Semipermeable barrier which surrounds the cell

Question 3

Cytoplasm

Answer 3

Gel like fluid which suspends organelles and is the site of metabolic processes

Question 4

Ribosomes

Answer 4

Site of protein synthesis (translation)

Question 5

70’s ribosomes

Answer 5

Prokaryotes -> found freely in the cytoplasm, smaller and lower in mass

Question 6

80’s ribosomes

Answer 6

Eukaryotes -> either bound to the RER (rough-endoplasmic-recitlilium) or free floating in the cytoplasm.

Question 7

Cell wall

Answer 7

provides shape and allows the cell to withstand turgor pressure

Question 8

Nucleoid DNA

Answer 8

‘Naked’ DNA (not associated with histone proteins) found looped in the nucleoid

Question 9

Nucleous

Answer 9

Contains DNA & the Nucleolus which is where ribosomes are made. Double-membrane allowing it to separate transcription and translation.

Question 10

Rough Endoplasmic Reticulum (RER)

Answer 10

Function in the synthesis (via bound ribosomes) and transport of polypeptides. Made up of connected sacs.

Question 11

Smooth endoplasmic reticulum (SER)

Answer 11

Synthesizes phospholipids and cholesterol to repair membranes. Made up of connected sacs which are continuous with the RER.

Question 12

Golgi Apparatus

Answer 12

Modifies polypeptides from the RER, packaging them into vesicles for transport: to lysosomes, out of the cell (exocytosis), or to the plasma membrane.

Question 13

Lysosome

Answer 13

Membrane-bound organelle containing digestive enzymes -> breaks down organelles, pathogens, and is responsible for cell death.

Question 13

Mitochondria

Answer 13

Surrounded by a double-membrane -> Produce ATP via aerobic cellular respiration.

Question 14

Vacuoles

Answer 14

Store water & maintain turgor pressure against the cell wall.