Fiser Chapter 1. CELL BIOLOGY Flashcards Preview

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Flashcards in Fiser Chapter 1. CELL BIOLOGY Deck (19)
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1

cell membrane composition

lipid bilayer with protein channels, enzymes, and receptors

2

What increases membrane fluidity?

Cholesterol

3

Membrane potentional

Cells are negative inside compared to outside due to Na/K ATPase (3 Na out, 2 K in)

Na gradient is used for co-transport of glucose, proteins, and molecules

4

Desmosomes/hemidesmosomes

Adhesion molecules (cell-cell and cell-extracellular matrix, respectively) which anchor cells

5

Tight junctions versus Gap junctions

Tight junctions: cell-cell occluding junctions; form an impermeable barrier (eg epithelium)

Gap junctions: allow communication between cells (connexin subunits)

6

G proteins

Intramembrane proteins; transduce signal from receptor to response enzyme

7

Ligan-triggered protein kinase

Receptor and response enzyme are a single trans-membrane protene (insulin, epidermal growth factor). Binding actiates the kinase domain, which phosphorylates substrate proteins.

8

Examples of glycolipids and glycoproteins on cell membrane

ABO bloody-type antigens: glycolipids

HLA-type antigens: glycoproteins (Gp)

9

Osmotic equilibrium

Water moves from area of low solute concentration to an area of high solute concentration and approach osmotic equilibrium

10

Cell cycle sequence

G1, S (proteine synthesis, chromosomal duplication), G2, M (mitosis, nucleus divides)

Can also go to G0 (quiescent) from G1

11

What detemines cell cycle length?

G1: growth factors affect cell here too

12

Mitosis

PMAT

Prophase (centromere attachment, spinder formation, nucleus disappears)

Metaphase: chromosome alignment

Anaphase: chromosomes pulled apart

Telophase: separate nucleus reforms around each set of chromosomes

13

Steroid and tyroid hormones

Both transcription factors (bind DNA and help transcription of genes), but steroid binds receptor in CYTOPLASMand then enters nucleus, while thyroid hormone binds receptor in nucleus

14

Purines and pyrimidines

Purines: adenine and guanine

Pyrimidines: cytosine, uracil (RNA), thymidine (DNA), "pyramids cut"

AU or AT is with 2 hydrogen bonds; GC is with 3 hydrogen bonds

15

Glycolysis overall does what?

Turns a glucose molecule into 2 ATP and 2 pyruvate

16

Krebs cycle overall does what?

Located on inner matrix of mitochondria, it takes the 2 pyruvate molecules created in glycolysis, to create NADH and FADH2. These then enter the ETC to create ATP. Overall 1 glucose creates 36 ATP

17

How much ATP does each glucose molecule create during aerobic metabolism?

Glycolysis then krebs cycle then ETC:
36 ATP

18

Gluconeogenesis overall

Lactic acid (from cori cycle) and amino acids are converted to glucose

Fat and lipids NOT available for gluconeogenesis because acetyle CoA (breakdown of fat metabolism) cannot be converted back to pyruvate

19

Cori cycle overall

Liver turns muscle lactate into new glucose; pyruvate plays a key role