LECTURE 4 WHY AND HOW CELLS DIVIDE Flashcards Preview

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Flashcards in LECTURE 4 WHY AND HOW CELLS DIVIDE Deck (24)
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1
Q

Recall cell structures from last time

A
  • Membranes
  • Nucleus (and nucleolus)
  • Chromosomes
  • Ribosomes
  • Endoplasmic Reticulum (RER and SER)
2
Q

Golgi Apparatus

A
  • Polarized stack of membranes
  • Enzymes modify proteins from ER
  • Add & modify sugars
  • Material moves between stacks via transport vesicles
  • Many final destinations
3
Q

Protein synthesis occurs in different places

Cytoplasmic proteins

A
  • Made of free ribosomes in the cytoplasm

* Proteins are soluble (hydrophilic)

4
Q

Protein synthesis occurs in different places

Membrane proteins and secreted proteins

A
  • 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!)
5
Q

Lysosomes: Acidic organelles

A

Digest food & polymers to recycle monomers

Phagocytosis
Autophagy

6
Q

Mitochondria:

A

makes ATP (energy for the cell)

7
Q

Cytoskeleton: support for the cell

A
  • Microtubules (tubulin)
  • Microfilaments (actin)
  • Intermediate Filaments (keratins +)
8
Q

How do cells divide?

Bacteria and mitochondria

A
  • Binary fission
  • One small circular chromosome is copied
  • Cell pinches between DNA molecules
  • Cytoplasm/matrix divides
9
Q

How do cells divide?

Eukaryotic cells

A
  • Many long linear chromosomes

* Need to evenly divide DNA so daughter cells get all info •After DNA is divided, cytoplasm and organelles divide

10
Q

Eukaryotes have two types of cell division

Growth and repair = MITOSIS

A

Two identical daughter cells

11
Q

Eukaryotes have two types of cell division

Reproduction = MEIOSIS

A

4 non-identical haploid cells from a diploid cell (sperm, eggs)

12
Q

THE CELL CYCLE

INTERPHASE:

A

G1 – grows, make proteins, lipids, and carbohydrates

13
Q

THE CELL CYCLE

•S

A

synthesizes DNA

14
Q

THE CELL CYCLE

•G2 –

A

finishes making proteins, membranes, gets ready to divide

15
Q

THE CELL CYCLE

Cytokinesis

A

the rest of the cell divides

16
Q

THE CELL CYCLE

Cytokinesis

A

the rest of the cell divides

17
Q

Phases of MITOSIS

A
  • PROPHASE
  • METAPHASE
  • ANAPHASE
  • TELOPHASE AND CYTOKINESIS
18
Q

Apoptosis

A

regulated cell death

19
Q

Meiosis

A

creates 4 non-identical haploid cells from 1 diploid cell

20
Q

Meiosis:

Interphase

A

DNA is replicated

* During S phase!

21
Q

Meiosis:

Meiosis I:

A

(Reductional division)

Homologous chromosomes separated

22
Q

Meiosis:

Meiosis II:

A

(Equational division)

Sister chromatids separated

23
Q

Mitosis

Prophase 1

A
  • Crossing over

* Creates recombinant chromosomes

24
Q

Mitosis

•Anaphase I:

A

•Separates homologouschromosomes•(Mitosis separates sister chromatids)