"Active Transport, Endocytosis and Exocytosis" Material Input and Output of Cells PPT

Description

"Active Transport, Endocytosis and Exocytosis" Material Input and Output of Cells PPT

Part 1: Essential knowledge and foundation of literacy

1. Active transportation

1.Transportation direction: from_______→_______.

2.Transportation conditions:

(1)_________________.

(2) It needs to consume the energy released by chemical reactions in cells.

3. Example: Glucose absorption by small intestinal epithelial cells.

4. Significance: To ensure that living cells can _______________, actively choose to absorb _______________, and excrete ____________________________.

【Doubtful】

Do animal cells necessarily absorb glucose the same way?

Tip: Not necessarily the same. Small intestinal epithelial cells absorb glucose through active transport, while red blood cells absorb glucose through assisted diffusion.

2. Endocytosis and exocytosis

Based on the transport characteristics of endocytosis and exocytosis, determine whether the following statements are correct or incorrect:

1. The way macromolecular substances enter and exit cells is endocytosis and exocytosis. ( )

2. The process of endocytosis depends on the fluidity of the cell membrane. ( )

3. The processes of endocytosis and exocytosis mainly rely on membrane deformation and do not require energy consumption. ( )

Tip: Endocytosis and exocytosis require energy.

4. As cells continue to undergo endocytosis, the area of ​​the cell membrane will become smaller and smaller. ( )

Tip: Biofilms can transform into each other, and there is a dynamic balance in the area of ​​cell membranes.

Active transport and endocytosis PPT, part 2 content: key capabilities and literacy formation

Knowledge point 1: Active transport, endocytosis and exocytosis

1. Comparison of active transport, endocytosis and exocytosis:

2.Characteristics of carrier protein:

(1) Specificity: When a carrier protein transports substances inside and outside the cell, it can only transport a unique type of substance or a type of substance with very similar properties.

(2) Saturation: The number of carrier proteins on the cell membrane is limited. During the transport process, when all carrier proteins have assumed the corresponding transport tasks, the transport speed will no longer be accelerated by other conditions.

【Think·Discussion】

Both cell membranes and organelle membranes are selective when absorbing substances, but because of their different functions, they choose to absorb different substances. Let's analyze the reasons for the selectivity difference between the two based on the composition of the membrane. (scientific thinking)

Tip: Proteins are the main carriers of life activities. Differences in membrane proteins lead to differences in selectivity.

【Literacy Case】

(Adapted from National Volume I in 2016) It is known that mitochondria can synthesize ATP, a high-energy substance, which can provide energy for life activities during the hydrolysis process. The ion pump is a carrier protein with ATP hydrolase activity that can transport ions across the membrane using the energy released by hydrolyzing ATP. Which of the following statements is correct ()

A. The transmembrane transport of ions through ion pumps is assisted diffusion

B. The transport of ions across the membrane through ion pumps proceeds along the concentration gradient.

C. Carbon monoxide poisoning in animals reduces the rate at which ion pumps transport ions across the membrane.

D. Adding protein denaturant will increase the rate of ion pump transporting ions across the membrane.

【Problem Solving Guide】

(1) Key questions: "ATP hydrolysis energy supply", "ion pump" and "ATP hydrolase activity" are the key information of the question.

(2) Judgment skills: Does not consume energy and does not require transport proteins → free diffusion; does not consume energy and requires transport proteins → assisted diffusion; consumes energy and requires carrier proteins → active transport.

Knowledge Point 2 Factors Affecting Material Transport Rate

1. Concentration difference:

(1) Since free diffusion does not require transport proteins and energy, the substance transport rate is proportional to the substance concentration.

(2) Since assisted diffusion and active transport require transporters, when all transporters are utilized, the transport rate of substances will reach the maximum (point P). At this time, the factor limiting the transport rate of substances is mainly the transporters. quantity.

(3) Since active transport can transport substances against the concentration gradient, when the intracellular concentration is greater than the extracellular concentration, substances can still be absorbed into the cell.

2.O2 concentration:

(1) The material transportation mode represented by Figure A is free diffusion or assisted diffusion.

(2) Picture B represents the active transportation mode.

①At point A, the energy required for material transportation is provided by anaerobic respiration;

②The AP section shows that as the O2 concentration increases, the energy generated by aerobic respiration increases and the rate of active transport increases.

③After point P, when the O2 concentration reaches a certain level, the transport rate will no longer increase due to factors such as the number of transport proteins.

3.Temperature:

(1) From the analysis of the structural characteristics of the cell membrane, temperature will affect the fluidity of the cell membrane and thereby affect the material transport rate.

(2) From a metabolic perspective, high or low temperatures will affect the activity of enzymes, thereby affecting the energy supply of cells and affecting the rate of material transport.

【Think·Discussion】

1. Although active transport can absorb substances needed by organisms against the concentration, if the concentration of external nutrients is too low, it will also affect the normal life activities of cells. Give an example to further explain. (concept of life)

Tip: Organisms have quantitative requirements for nutrients. If there are too few relevant nutrients in the outside world, active transportation cannot meet the needs of organisms. For example: In iodine-deficient mountainous areas, people in this area often suffer from "big neck disease" due to nutritional deficiencies. Plants deficient in magnesium will cause their leaves to turn yellow.

2. The inner membrane of the mitochondria contains a protein, and H+ can pass through this protein along the concentration difference. What function does this process reflect? (Concept of Life)

Tip: As a transporter, it embodies the transport function of proteins.

【Literacy Case】

Studies have found that there are two carriers for transporting glucose on the microvilli surface of small intestinal villi-SGLT1 and GLUT2. The former is an active transporter and the latter is a transporter that assists diffusion. Scientists draw the curve shown in the figure based on the transport rate under different glucose concentrations. Which of the following statements is incorrect ()

A. When cells transport glucose, the maximum rate of assisted diffusion is about three times the maximum rate of active transport.

B. At lower concentrations, active transport carriers reach saturation first

C. Small intestinal villus cells transport glucose in two ways at the same time

D. At higher concentrations, cells mainly rely on active transport to increase the absorption rate

【Problem Solving Guide】

(1) Key points for review: "SGLT1 - transporter for active transport", "GLUT2 - transporter for assisted diffusion", "abscissa - glucose concentration".

(2) Key to the curve: As the glucose concentration changes, pay attention to the difference in the changing trends of the two curves.

[Analysis] Choose D. It can be seen from the figure that when cells transport glucose, the maximum rate of assisted diffusion is about 30 and that of active transport is about 10, so A is correct; at lower concentrations, active transport reaches saturation first, so B is correct; the villi cells of the small intestine have two effects on glucose. Both modes of transport are carried out simultaneously, so C is correct; at higher concentrations, cells mainly rely on assisted diffusion to increase the absorption rate, so D is wrong.

Keywords: Free download of the PPT courseware for high school biology compulsory course 1 from the People's Education Press, PPT download of active transport and endocytosis and exocytosis, PPT download of material input and output of cells, .PPT format;

For more information about the PPT courseware "Material Input and Output of Cells Active Transport and Endocytosis and Exocytosis", please click the Material Input and Output of Cells ppt Active Transport and Endocytosis and Exocytosis ppt tag.

"Passive Transport" Material Input and Output of Cells PPT:

"Passive Transport" Material Input and Output of Cells PPT Part One Content: Foundation of Essential Knowledge Literacy 1. Principle of water entering and exiting cells 1. Osmosis: (1) Meaning: Water molecules (or other solvent molecules) pass through _______ diffusion. (2) Direction: from __________..

File Info

Update Time: 2024-09-08

This template belongs to biology courseware High School Biology Compulsory Course 1, published by People's Education Press industry PPT template

Preview