Cell Structure
Cells are not the same because they can have different shapes, cells with different shapes have different purposes or functions. A cells shape reflects it's function.
Are all cells the same?
Cells are not the same shape. A cell may grow large in one or two dimensions but remain small in others.
Are all cells the same?
1. CELL MEMBRANE: layer that covers the cells surface and acts as a barrier between the inside of a cell and a cell's environment. 2. CYTOPLASM: The part (or region) of a cell within the membrane. Contains fluid and structures in the fluid. 3. RIBOSOME: Structure where protein is made (protein synthesis) 4. DNA: Genetic material that gives instructions for making proteins, regulating cellular activities and allows cells to reproduce.
Describe the 4 structural features all cells have in common.
1. All living things are made up of cells. 2. They obtain energy 3. respond to their environments 4. reproduce.
How do living things differ from nonliving things?
3.5 billion years ago or more
How long have bacteria been on earth?
100 trillion cells
How many cells are in the human body?
1. Single loop of DNA:lies near the center of the cell. 2. Ribosomes: where protein synthesis happens 3. Cytoplasm: part of the cell inside the membrane. 4. Cell wall that surrounds the cell membrane 5. capsule surrounds the prokaryotic cell walls and allows them to cling to surfaces like teeth, skin and food.
Identify the 5 main features or parts of a prokaryotic bacterial cell.
Cells were discovered by Robert Hooke in 1665
In what year were cells discovered and by whom?
It is better to be a small cell because small cells have greater surface area-to-volume ratios and can exchange substances more efficiently.
Is it better to be a large or a small cell?
1. cellular organization 2. Homeostasis 3. Metabolism 4. Responsiveness 5. Reproduction 6. Heredity 7. Growth
List the 7 characteristics of cells
The microscope
The invention of what instrument allowed us to see cells?
1. nucleus 2. membrane bound organelles
What 2 features make eukaryotic cells different from prokaryotic cells?
Structures that carry out specific activities inside the cell.
What are organelles?
He discovered single celled organisms in pond water he called "animalcules".
What did Anton van Leeuwenhoek discover in 1675?
He concluded that cells make up every part of a plant.
What did the German botanist, Matthis Schleiden conclude in 1838?
He proposed that cells come only from the division of existing cells.
What did the German physician (doctor) Rudolph Virchow propose?
He concluded that animals are also made up of cells.
What did the German zoologist, Theodor Schwann conclude in 1839?
1. All living things are made up of one or more cells. 2. Cells are the basic units of structure and function in all organisms. 3. All cells arise from existing cells.
What does the CELL THEORY state about cells?
Bacteria
What group of organisms are prokaryotes?
A scientist who studies plants.
What is a botanist?
An organism that is made up of cells that have a nucleus and membrane-bound organelles Make up multicellular organisms.
What is a eukaryote organism?
A scientist who studies animals.
What is a zoologist?
The cell size is limited by a cell's surface area-to-volume ratio.
What limits the size that a cell can grow to?
The cell membrane represents a cell's surface area.
What part of a cell represents its surface area?
The cytoplasm represents a cell's volume.
What part of the cell represents its volume?
Cells release WASTE from their cytoplasm.
What substances do cells need to release from their cytoplasm?
Cells take NUTRIENTS into their cytoplasm.
What substances do cells need to take into their cytoplasm?
Eukaryotic cells
What type of cells are all multicellular organisms made of?
1.5 billion years ago
When did Eukaryotic cells first appear on Earth?
Smaller cells
Which cells have greater surface area-to-volume ratios?
Eukaryotic cells carry out more specialized functions.
Which cells, prokaryotic or eukaryotic carry out more specialized functions?
Because cells are the basic unit of life. By studying cells we can better understand life's processes.
Why are we studying cells?
Because they reminded him of the small rooms that monks lived in called cells.
Why did Hooke name his discovery cells?
Cells must be small because as the cell gets larger, it takes up more nutrients and releases more waste. The nutrients and waste have to move farther to reach their destination in a larger cell.
Why must cells be small?