Download Cells - Life Learning Cloud

MAKING SENSE OF
CELLS
Biology
1.1 Life Processes – Cells
Image © Depositphotos.com/[julos #4371007]
• Can you remember the processes in MRSGREN that
are common to most living things?
• Can you recognise cell structures such as the
nucleus, cytoplasm, cell membrane, cell wall,
chloroplast and vacuole, and describe their
functions?
• What are the major differences between plant and
animal cells?
• MRS GREN stands for the 7 characteristics of living
things.
• All living organisms from a simple bacteria to plants
and animals, can do all of these processes.
• All living organisms are composed of cells.
• The simplest organisms are made of one single cell.
• More complex organisms like animals and plants are
made of many cells and are called multicellular
organisms.
• In multicellular organisms there are many different
types of cells that are specialised to carry out
particular functions.
Cell membrane
Cytoplasm
Nucleus
Mitochondria
Cell wall
Cell membrane
Mitochondria
Vacuole
Cytoplasm
Chloroplast
Nucleus
•
•
•
•
•
Largest organelle.
Controls the activities of the cell.
Contains chromosomes.
Chromosomes carry genes.
The genes determine which proteins the cell
can make.
Nucleus
• Forms a boundary between the cytoplasm and
the outside of the cell.
• Some chemicals can pass through this barrier
and the cell can control what comes in and out.
• It is selectively permeable.
• Jelly like substance which contains all of the
organelles.
• Many of the cell’s chemical reactions take place
in the cytoplasm.
• These are called metabolic reactions.
Cytoplasm
• Carry out some of the reactions of respiration.
• Therefore releasing energy for the cell.
• Cells that have a high demand for energy
usually have many mitochondria.
Ribosmes
Protein Made here.
• Found only in plant cells.
• It is made of a non-living material called
cellulose.
• Helps the cell keep its shape.
• It is freely permeable.
Cell wall
•
•
•
•
Found in some plant cells.
Contains chlorophyll.
Chlorophyll is a green pigment.
It absorbs light energy to make food in the
process of photosynthesis.
• Found only in plant cells.
• Filled with cell sap.
• Cell sap is a store of dissolved sugars, mineral
ions, and other solutes.
• Helps keep the cell’s shape.
Vacuole
Cell structure
Plant or animal cell
Function
Nucleus
Both
Controls the activity of the cell using genes
Cell Membrane
Both
Controls what enters and leaves the cell
Cytoplasm
Both
Location of cell metabolic reactions
Mitochondria
Both
Site of respiration
Cell Wall
Plant only
Made of cellulose, gives cell strength
Chloroplast
Plant only
Site of photosynthesis
Vacuole
Plant only
Contains cell sap which helps keep cell’s shape