1. Life 1

2. What is a scientific theory?
A scientific theory is an explanation of some aspect of the natural world that can, in accordance with the scientific method, be repeatedly tested, using a predefined protocol of observations and experiments.
Established scientific theories have withstood rigorous scrutiny and are a comprehensive form of scientific knowledge.
What is a scientific theory?

3. Stephen Jay Gould said, “
Stephen Jay Gould said, “...facts and theories are different things…Facts are the world’s data. Theories are structures of ideas that explain and interpret facts.”
QUOTE

4. TRUE, or FALSE? Nonliving things have cells.
Cells are made mostly of water.
Different organisms have cells with different structures.
All cells store genetic information in their nuclei.
Diffusion and osmosis are the same process.
ATP is the only form of energy found in cells.
Cellular respiration occurs only in lung cells.
TRUE, or FALSE?

6. Discovered cells in 1665 using a microscope – cork!
ROBERT HOOKE

7. Cell theory All living things are made of cells
The cell is the smallest unit of life
All new cells come form preexisting cells
GET READY TO READ - 41
Cell theory

8. Unicellular or Multicellular?

9. Characteristics of Life
Growth and Development
Reproduction
Responses to Stimuli
Homeostasis
Energy
Characteristics of Life

10. Growth and development
By increasing cell size and/or increasing cell number
Growth and development

11. How many bacteria will there be after 2 hours if a single bacteria doubles itself every 20 minutes?
20 min = 2 ; 40 min = 4 ; 60 min = 8…
- When a bacterium experiences growth by dividing, the multiplication rate exceeds the death rate.
- Bacteria will keep dividing until they run out of food and waste products build up. Then, the bacterial death rate will exceed the multiplication rate.
Doubling BACTERIA

12. Living things make more living things through the process of reproduction
Two types: asexual and sexual
Reproduction

13. Adjust and respond to changes in their internal and external environments
Responses to stimuli

14. WHITE BLOOD CELL vs bacteria
WHITE BLOOD CELL vs bacteria

15. Homeostasis Living things maintain stable conditions
Why is maintaining homeostasis important to organisms?
Homeostasis

16. energy Living things use energy for all the processes they perform
Get energy by making their own food, eating food, or absorbing food
energy

17. What happens if (blank) disappeared?

18. Basics Mostly water (70% volume of a cell) 4 Macromolecules
The size and shape of a cell relates to its job or function i.e. blood
Hundreds of different types in the human body
Basics

19. Water is the single most abundant chemical found in living things.
Virtually all chemical reactions in life processes take place in solution in water.
Some organisms can live in a dormant and desiccated state for long periods of time but require water to become active.
Water is present both inside and outside cells.
With assistance from helpful enzymes, the addition and subtraction of water molecules enables the construction and demolition of carbohydrates, fats and proteins.
WATER – THINGS TO KNOW

20. MACROMOLECULES

22. Prokaryotic and Eukaryotic Cells
A prokaryotic cell is like a one room cabin – no internal membranes!
A eukaryotic cell contains membrane bound organelles – different compartments!
Take a moment and look at yourself. How many organisms do you see?
You are home to around 100 trillion bacterial cells, which outnumber your own human cells by about 10 to one^1
Prokaryotic and Eukaryotic Cells

23. PLASMA membrane and cytoplasm
Like a bag of goo.
PM like the bag, cytoplasm like the goo
The membrane is a delicate, two-layered structure of lipids and proteins, and it controls what can enter and exit the cell.
The cytoplasm of a eukaryotic cell consists not only of cytosol—a gel-like substance made up of water, ions, and macromolecules—but also of organelles and the structural proteins that make up the cytoskeleton, or "skeleton of the cell."
PLASMA membrane and cytoplasm

24. Both prokaryotic and eukaryotic cells have a plasma membrane, a double layer of lipids that separates the cell interior from the outside environment. This double layer consists largely of specialized lipids called phospholipids.
Contains proteins
The plasma membrane is the border between the interior and exterior of a cell. As such, it controls passage of various molecules—including sugars, amino acids, ions, and water—into and out of the cell.
Fluid mosaic
Plasma membrane

25. Plasma membrane

26. BUBBLES vs. Membranes

27. In eukaryotic cells, which have a nucleus, the cytoplasm is everything between the plasma membrane and the nuclear envelope.
In prokaryotes, which lack a nucleus, cytoplasm simply means everything found inside the plasma membrane.
One major component of the cytoplasm in both prokaryotes and eukaryotes is the gel-like cytosol, a water-based solution that contains ions, small molecules, and macromolecules.
The cytoskeleton, a network of fibers that supports the cell and gives it shape, is also part of the cytoplasm and helps to organize cellular components.
Where protein synthesis takes place!
Like Jello!
cytoplasm

28. cytoplasm