III. HOAT DONG DAY-HOC 1 Kiem tra
2. Co che hinhthanh dien the ngh
- GV cho HS quan sat tranh hinh 28.2, 28.3 trang 115 SGK co ban. hinh 28.2 trang 109 SGK sinh hgc nang cao.
- GV neu yeu cau
Quan sat va trinh bay co che hinh thanh dien the nghi.
- GV ggi y:
+ Chi ra su chenh lech ion K"^ va Na'
+ Su di chuyen cia cac ion.
+ Tinh tham ciia mang te bao ddi vdi ion.
+ Hoat dong ciia bom Na, K.
- GV chiia bai bang each chieu dap an ciia nhdm len may chieu hay de cac nhdm ghi ket qua len bang.
- GV nhan xet, danh gia va bd sung hoan thien kien thiic.
HS hoat dong nhdm + Ca nhan nhan biet kien thiic tii viec quan sat tranh.
+ Trao ddi trong nhdm v6
cac van de GV ggi y.
thdng nha't y kien tra Idi ghi lai tren giay.
- Dai dien nhdm trinh bay tren tranh, Idp nhan xet va bd sung.
2. Co che hinh thanh dien the nghi dien the nghi
Co che:
- Cd su chenh lech vt
nong do Na"" va K"^ giiia dich md va dich bao (trong va ngoai mang).
* Lien he: GV giang giai: Con ngudi da ung dung dien te bao vao nhi6u llnh virc trong cuge song.
Do dien the ciia dia phoi triing gia cam de xac dinh miic song cua ga, vit ngay tCr ngay dau phat trien ciia ph6i. Tren co so dd chgn triing td't tiep tuc cho a'p nd, loai bd triing xau.
+ Nong do K"* trong dich bao Ion hon ngoai dich md.
+ Nong do Na"" trong dich md Idn hon dich bao. - K"" cd xu hudng di chuyen ra ngoai mang. - Na* cd xu hudng di chuyen vao trong mang thuan gradian ndng do. - Trang thai nghi mang CO tinh tha'm chgn Ige ddi vdiK*
+ Kenh K* md -^ K" di ra kenh Na"" ddng.
- K"" di ra mang dien duong (+) bi anion (-) giii lai nen khdng di ra xa khdi mang.
- Bom Na" / K"' thudng xuyen chuyen Na' ra va K"^ vao nen duy tri dugc tinh dn dinh tuong ddi ciia dien the nghi.
Hoqt dong 2. TIM HIEU DIEN THE HOAT D O N G
Muc tieu:
- HS trinh bay dugc khai niem dien the boat ddng, co che hinh thanh dien thd' boat dong.
- HS biet lien he thuc ti6n.
Hoqt dong ciia GV
- GV treo tranh hinh dd thi dien the boat dong va yeu cau HS:
+ Quan sat d6 thi
+ Tra Idi cau hdi: The nao la dien the boat dong?
- GV nhan xet, danh gia va giiip HS hoan thien kien thiic.
Hoqt dong cua HS
- HS boat dong dgc lap
vdi SGK va hinh ve. - Yeu cau chi ra dugc: + Khi cd kich thich tdi ngudng te bao than kinh hung pha'n.
+ Bien ddi dien the nghi thanh dien the boat dong. - Dai dien HS trinh bay
—> Idp nhan xet, bd sung.
Noi dung
1. Khai niem
Dien the boat dong phat sinh la do su chenh lech ciia dien the giiia vung boat dong va vung yen tinh.
- VCing da hung phan mang dien tich am, cdn vung yen tinh mang dien tich duong.
- GV yeu cau HS:
+ Quan sat hinh 28.3 va dgc thdng tin SGK muc 11.1 trang 110.
+ Chii thich vao do thj 28.3 cac giai doan phan cue, dao cue, tai phan cue.
+ Tra Idi cau hdi:
Nguyen nhan nao dSn den hien tugng mat phan cue, dao cue, rdi lai tai phan cue.
- GV yeu cau:
+ Quan sat hinh 28.2 va hinh 28.3.
+ Phan tich su di chuyen ciia cac ion Na" va K* qua mang va tac dung ciia su di chuyen nay.
- GV nhan xet, danh gia va giiip HS hoan thien kien thiic.
- HS phan tich van dung kien thiic d boat dong 1 de khai quat.
Hien tugng phan cue, dao cue, tai phan cue la do mang bi thay ddi dien the giua trong va ngoai mang ciia te bao.
- HS hoat dong nhom. + Ca nhan nhan biet kien thiic tCr viec phan tich tranh hinh.
+ Trao ddi trong nhdm th6'ng nhai y kien.
- Yeu cau neu dugc: + Chenh lech ndng do Na", K'^ trong va ngoai mang liic binh thudng. + Khi bi kich thich do cac kenh Na"", K'" md nen ion Na*, K* di chuyen 6 at gay ma't phan cue va dao cue -» xuat hien dien the hoat dong.
- Dai dien nhdm trinh bay tren tranh hinh -^ lop nhan xet.