B2. Cells

(0654) Coordinated Sciences 2023/2024

Subheadings and Key concepts

B2.1. Cell structure

• characteristics of plant cells + animal cells
• magnification
• specialized cells

B2.2 Movement in and out of cells

• diffusion + factors affecting diffusion
• osmosis
• investigating osmosis
• effects of osmosis on plant and animal cells

3.3. Active transport

Active transport:

• the movement of particles through a cell membrane 
• from a region of lower concentration 
• to a region of higher concentration 
• using energy from respiration

*Attn!: this is against the concentration gradient. It is like swimming against the current of water, and therefore, requires energy.

3.2. Osmosis

Don't let the names trick you! Diffusion and osmosis operate by the exact same mechanism. 

It's just that diffusion refers to many types of molecules whereas osmosis is EXCLUSIVE to water diffusing through a partially permeable membrane.

3.1. Diffusion

 

Diffusion is the net movement* of particles 

• from a region of their higher concentration 
• to a region of their lower concentration 
• down a concentration gradient, 
• as a result of their random movement

2.3. Size of specimen

A microscope makes a specimen look larger than its actual size. You'll need to know how to calculate the magnification and actual size of the specimen.

2.2. Levels of organisation

Multicellular plants and animals contain many different types of cells. Each type of cell is designed for a particular function.


Levels of organisation: cell --> tissue --> organ --> organ system --> organism

2.1. Cell structure and organisation

Most living things are made up of cells that act as building blocks of an organism. Cell shape varies based on its function.

Plant cells are usually larger than animal cells.

02. Cells pdf

# 20 Summary of Cells

Here is a brief summary of previous topics. 

#19 Active transport

Sometimes substances are required to be move against the Concentration Gradient, or faster than they would by Passive Transport. In these cases, Active Processes are used, which require energy.

#18 Osmosis

Osmosis is the diffusion of water molecules from a region of their higher concentration to a region of their lower concentration, through a partially permeable membrane. 

#17 Diffusion

Diffusion is the net movement of molecules from a region of its higher concentration to a region of its lower concentration. Molecules move down a concentration gradient, as a result of their random movement. 

#16: Tissues, Organs and organ Systems

Cells are organized to form tissue, organs, and organ systems. In a healthy organism, all the systems work together. 

#15 Cell functions

Multicelullar plants and animals contain many different types of cell. Each type of cell is design for a particular function. 

#14: Cell structure

Most living things are made of cells. Cell shape varies according to its function. Plant and animal cells differ in size, shape and structure (plants cells are usually larger than animal cells).