CELLS Topic 1 Biology 2012

What are living things made of? Living things are made up of cells Cells are the building blocks of life They come in all shapes and sizes. Some organisms are made up of only one cell and are called uni-cellular. Others are made up of lots of cells and are called multi- cellular. Cells work together and carry out the seven life processes that are needed for an organism to stay alive.

Seven life processes aka Characteristics of Living Things All living things do the following Watch the You tube clip to identify the 7 characteristics of living things http://www.youtube.com/watch?v=aynclw6TXeE&feature=related

Seven life processes aka Characteristics of Living Things Seven life processes aka Characteristics of Living Things All living things do the following; Not musically inclined, try this useful pneumonic.

The Cell Theory 1. All organisms are made up of one or more cells. 2. The cell is the basic LIVING unit of organization for all organisms. 3. All cells arise from pre-existing cells.

Cells ~ Basic building blocks There are 2 main types of cells; PROKARYOTIC CELLS EUKARYOTIC CELLS Eukaryotic cells are complex Prokaryotic cells are more basic

Prokaryotic Cells Are extremely small Have simple internal structure No membrane-bound organelles No membrane-bound nucleus Kingdoms they belong to are; Monera (bacteria) Archaea

Generalised Prokaryotic cell

Eukaryotic Cells Can be single celled organisms Can be Multicellular organisms Have a complex internal structure Have membrane-bound organelles Have a membrane-bound nucleus Kingdoms they belong to are; Plantae Animalia Protista Fungi

Generalised eukaryotic cell Animal cell Plant cell

Cell Size + Specialisation Cell specialisation refers to cells that have taken on special features to enable them to carry out their task. This is critical for multicellular organisms. Size is an important factor in the functioning of cells The cell must be able to efficiently remove wastes and obtain its requirements. The rate of outward movement of wastes and inward movement of requirements will influence the size to which the cell will grow.

Cell Size Cells are measured in: Microns  μm = 10-6 of a metre Nanometres  nm = 10-9 of a metre

Plants + animal Cells plant cell animal cell nucleus cytoplasm Animal and plant cells come in different shapes and sizes, but they all have three basic features or parts known as organelles plant cell animal cell nucleus cytoplasm cell membrane Plant cells also have some extra features that make them different to animal cells.

Organelles: Taking on Different Jobs Boundary – plasma membrane Power Supply – mitochondria Building Cell Structures – ribosomes Supporting Cell Structures – cytoskeleton Transport with the Cell – endoplasmic reticulum Packaging & Distribution – golgi apparatus Recycling & Reuse – lysosomes Moving in & out – endocytosis & exocytosis Coordinating cell activities – nucleus

Specialised structures in plants Chloroplasts – needed for photosynthesis (contain chlorophyll) Vacuoles (organelles) – for storage of sugars, minerals, proteins & water. They are much bigger in plants than in animals. Can you think of why this might be?

Cell Movement Cells need to be able to move around in order to meet their requirements for survival or to perform a specific function. ACTIVE MOVEMENT Cells can move due to specialised structures such as FLAGELLA & CILIA PASSIVE MOVEMENT Cells move about because the medium in which they are located moves them. For example; blood moves RBC’s

Flagella Cilia

How is the body organized? A school is made up of an organized system. Individual pupil Registration group Subject class Year group School

Structure of organisms Similarly to the school, the structure of multicellular organisms is based around the following ‘levels’ of organisation: CELLS TISSUES ORGANS SYSTEMS WHOLE ORGANISM Ultimately, the survival ability of each organism depends upon the functioning of all its individual cells.