Term 1 - walkins Flashcards Preview

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Flashcards in Term 1 - walkins Deck (41):
1

Size of Resting membrane potential is governed by __(how many) factors:________

- The permeability of the neuronal membrane
- Unequal distribution of different ions

2

There is more K+ ion in ICF than ECF T/F

true

3

Thee is more Na+in ICF than ECF T/F

False

4

The electrogenic pump operate as every ___ _______ ion ____, every ___ _______ions ____

every 3 Na+ out, every 2 K+ in

5

3 factors that cause the unequal distribution of ions when neuronal membrane at rest

- some - ve charged proteins (Pr-) are trapped in cell because of their large size
- Operation of ATPase ( the electrongenic pump)
- Presence of special ion channels in membrane

6

Two types of ion channels

- Passive channels, which ions can go through continuously
- Active Channels that are gated

7

types of active ion channels

- membrane potential (Voltage regulated gates )
- Neurotransmitter (Chemical regulated gate)

8

When neuronal membrane at rest, it is impermeable to ____ ion, but permeable to ____ion

impermeable to Na+ but permeable to K+

9

K+ ions can't diffuse out of neuronal membrane T/ F?

False
they can diffuse out until the equilibrium of K+ is reached

10

What is depolarisation ?

- 70mV changes to +40mV

11

What is Hyperpolarisation?

- 70mV changes to -90mV

12

what is Em

Membrane potential

13

What is repolarisation?

when membrane potential go backs to -70mV

14

Function of different components of a neuron

Dendrites- reception of income information
Soma- Cell body, contain nucleus & most organelles)
Nucleus
Axon- Transmit the electrical impulse (action potential)
Axon hillock- where axon originates & action potential initated
Axon terminals - Release neurotransmitter
Schwann cell
Node of Ranvier

15

Types of ions channel in neuron

~ Ligand - gated channel - response to ligand binding
~ Voltage- gated channel - response to change in membrane potential
~ passive Channel

16

Cells of Nervous system

- Neurons - excitable cell
- Glial cells - support cells

17

Passive channels can be found______

throughout the neuron; at resting Em

18

Ligand- gated channels can be found __________

Dendrites & cell body; for synaptic potential

19

Voltage gated channels can be found _________

- Na+ & K+ channel: throughout, but more in axon (especially in axon hillock); for action potential
- Ca- channels: Axon terminals; Release of neurotransmitter

20

Local potential is the results of _______ ___________ stimulation of neuron

sub- threshold stimulation

21

Local potential takes places because _______

the stimulus is not strong enough to generate the action potential

22

Size of local potential is depends on ________

the strength of the stimulus

23

local potential is also called ?

graded potential

24

local potential travel short distant and they can summate T/F

True

25

Local potential is important for ____________

synaptic transmission & forms basis of generator potential (sensory potential)

26

Threshold potential is ____mV

-55mV

27

local potential at synapses, can either________(___polarisation) or ____________ (___polarisation)

excitatory (depolarisation) or inhibitory (hyperpolarisation)

28

Excitatory local potentials are caused by _________

small number of membrane Na+ ions channel opened

29

Inhibitory local potential caused by _________

small number of K+ / Cl- membrane ion channel opened

30

Neuronal membrane is polarized > ______ +ve; ________ -ve

outside +ve; inside -ve

31

Glycoprotein is important for __________

self recognition of cell

32

Name the steps of mitosis

interphase > prophase > prometaphase> metaphase > anaphase > Telophase > Cytokinese

33

Describe prophase

- DNA has been condense into chromosome.
- Nuclear envelop breaks down
- Centrioles moving to opposite pole

34

Describe interphase

G0 – Carry out physiological function > G1 – Growth, major part of cell life span > S – DNA replication, cell then contain 2 identical DNA copies > G2 – Growth, DNA condense into compact bodies

35

What is tetrad

a group of four closely associated chromoatid of homologous pair formed by synapsis
only happen in Meiosis I

36

Describe Metaphase

Chromosomes line up at the metaphase plate with mitotic spindle fibre attached to their centromere

37

Describe Anaphase

- Spindle fibre shorten and chromosomes been pulled apart towards the opposite poles. the sister chromoatids been seperated

38

Describe Telophase

- Nucleus envelop reformed
- mitotic spindle fibre breaks down
- Chromosomes start to uncoil
- cytoplasm dividing.

39

Describe Cytokinesis

Cytoplasm becomes separated and two daughter cells are formed

40

How many chromosome there should be?

46 Chromosome (23 pairs)

41

What is synapsis?

- Homologous chromosomes lined side by side and forms tetrad
- Happen in meiosis prophase I
- Allow cross-over at the chiasma happen