LECTURE 3 Cells and Chromosomes

Question 1

All cells have

Answer 1

• DNA (genetic info)
• Ribosomes (make proteins)

Question 2

Prokaryotes

Answer 2

—no nucleus

• Bacteria
• Archaea

Question 3

Eukaryotes

Answer 3

Have nucleus and other organelles

Question 4

Multicellular organisms (eukaryotes)

Every cell has the same DNA (information)

•Except?

Answer 4

red blood cells and gametes

Question 5

Different cell types EXPRESS different genes

Answer 5

DIFFERENTIATION – cell is specialized

Question 6

The Plasma Membrane

Answer 6

•Lipid bilayer with proteins and

carbohydrates

Selective Barrier

• Separates cell from the environment
• Lets some materials across to keep the cell functioning properly
• Similar structure for organelle

membranes

Question 7

DNA + protein =

Answer 7

chromatin

Question 8

Euchromatin=

Answer 8

• Loosely packed
• Interphase
• Active genes

Question 9

Heterochromatin

Answer 9

• Tightly packed
• Metaphase
• Inactive genes

Question 10

(Endoplasmic Reticulum)

Rough ER (RER)

Answer 10

• Bound ribosomes
• Synthesis of secreted proteins and glycoproteins

Question 11

(Endoplasmic Reticulum)

Smooth ER (SER)

Answer 11

• Lipid Synthesis
• Membrane synthesis

Question 12

Golgi Apparatus

Answer 12

• Polarized stack of membranes
• Enzymes modify proteins from ER
• Add & modify sugars
• Material moves between stacks via transport vesicles •Many final destinations

Question 13

Protein synthesis occurs in different places Cytoplasmic proteins:

Answer 13

• Made of free ribosomes in the cytoplasm
• Proteins are soluble (hydrophilic)

Question 14

Protein synthesis occurs in different places

Membrane proteins and secreted proteins:

Answer 14

• Made on ribosomes bound to the ER
• Sorted in the Golgi apparatus
• Membrane proteins are hydrophobic or amphipathic •Secreted proteins can be either hydrophilic or hydrophobic (or amphipathic!)

Question 15

Lysosomes: Acidic organelles ?

Answer 15

Digest food & polymers to recycle monomers Phagocytosis and Autophagy

Question 16

Mitochondria?

Answer 16

makes ATP (energy for the cell)

Question 17

Sperm delivers…

Answer 17

DNA (genetic information) – the egg provides everything else

Question 18

Cytoskeleton

Answer 18

Support for the cell

• Microtubules (tubulin)
• Microfilaments (actin)
• Intermediate Filaments (keratins)
• Other proteins link these structures together

Question 19

Diploid and Haploid

Answer 19

Diploid cells contain two complete sets (2n) of chromosomes. Haploid cells have half the number of chromosomes (n) as diploid - i.e. a haploid cell contains only one complete set of chromosomes. Cell Division and Growth. Diploid cells reproduce by mitosis making daughter cells that are exact replicas.

Question 20

Endosymbiosis

Answer 20

symbiosis in which one of the symbiotic organisms lives inside the other.

Question 21

CELL STRUCTURES

Answer 21

Question 22

Sandwich model

Answer 22

Question 23

Difference between Nucleus and Nucleolus

Answer 23

Nucleus stores DNA;

Nucleolus makes

ribosomes

Question 25

What does Ribosomes make?

Answer 25

Proteins