What is Life?

What is Life?

Bio – logy: The study of Life

Organism: Any living thing

Key Vocabulary Terms

Cell

Unicellular

Multicellular

Differentiation

Homeostasis

Reproduction

Growth

Development

Prokaryote

Eukaryote

Organelle

Consumer

Producer

Energy

Photosynthesis

Cellular Respiration

Definitions• Cell:

Basic functional and structural unit of all organisms. – Performs specific functions– Provides shape / structure

• Unicellular: organisms made up of only one cell. (Uni = one)

• Multicellular: organisms made up of more than one cell. (multi = more than one)

Definitions (continued)

• Differentiation:

When the cells of multicellular organisms become different from each other as they multiply and begin to perform specific functions according to their genetic instructions.

Definitions (continued)• Autotroph (-ic):

An organism that produces its own food.-photosynthetic organisms;

AKA: “Producers”Example: plants

• Heterotroph (-ic):An organism that must obtain its food from another source. -organisms that can not photosynthesize;

AKA: “Consumers” Example: humans

Definitions (continued)

• Organelle: “Mini” Organs within a cell that carry out specific functions.

Some organelles are “membrane-bound” which means they are surrounded by their own individual membrane.

Examples: nucleus, mitochondria, chloroplasts

Definitions (Continued)

• Cell Membrane: Outer “covering” of the cell which acts as a “gate-keeper” and determines what may enter and leave the cell.

The cell membrane is “semi-permeable” or “selectively permeable” which means it will allow some substances to enter the cell and block other substances from entering.

Definitions (continued)• Prokaryote (-ic):

-Bacteria cells-Simple cell type

-no membrane bound organelles

• Eukaryote (-ic):-Term used to describe more complex cell types.

-All organisms EXCEPT bacteria are made of Eukaryotic cells, including single celled protists.

-This cell type contains many organelles, including the following “membrane-bound” organelles: Nucleus, Mitochondria, and Chloroplasts.

Characteristics of Life

ALL LIVING THINGS:

1. Are Made of Cells

2. Display Organization

3. Growth & Development

4. Reproduce

5. Respond to Stimuli

6. Require/Use Energy

7. Pursue Homeostasis

8. Evolve Adaptations

Characteristics of Life

1. Cells-– All organisms are made of cells. – Some organisms are unicellular and some

are multicellular– There are two types of cells:

• Eukaryotic• Prokaryotic

*Compare and contrast Eukaryotic and Prokaryotic cells*

Characteristics of Life2. Reproduction-

The process by which organisms produce new organisms.

-All living organisms reproduce.

Two Types of Reproduction:

1.) Sexual: -Requires two parents (Two cells)-Offspring genetically different from parents

2.) Asexual:

-Only one parent (one cell) is involved-Offspring genetically identical to parent or parent

cell. (Clones)

3. Growth-

Organisms use materials and energy from their environment to increase in size.

GROWTH = INCREASE IN SIZE

Growth occurs two ways:

a) Cell grow in circumference

b) Cells multiply/reproduce (divide)

Characteristics of Life

4. Development-

Changes that occur during growth, i.e. differentiation.

*Contrast Growth and Development*Growth = increase in size

Development = changes occuring during growth

Characteristics of Life

5. Response-

Organisms respond to their environment

(i.e. plants respond to sunlight)

6. Adaptation-

Organisms develop traits that make them better able to survive in their environment.

(i.e. Natural Selection)

Characteristics of Life

7. Homeostasis-

A stable level of internal conditions. All living organisms strive to establish and maintain homeostasis. (i.e. Blood Pressure and Thermoregulation)

Characteristics of Life

8. Energy Use-

Energy: The ability to do work

Food = NRG sourcePrimary energy source = Carbohydrates

Secondary energy source = Lipids/Fats

Tertiary energy source = Proteins

Characteristics of Life

8. Energy Use (cont.)-

ANIMALS = HETEROTROPHS:Take in food (NRG), break it down, and build long

chains of glucose molecules which are stored in the liver as “GLYCOGEN”

PLANTS = AUTOTROPHSFood (NRG) produced as a byproduct of

photosynthesis and stored in the plant as long chains of glucose called “STARCH”

Characteristics of Life

8. Energy Use (cont.)-

• Photosynthesis:– Process used by plants to convert CO2,

water and sunlight to stored NRG (starch)

Characteristics of Life

8. Energy Use (cont.)-

The stored forms of NRG, glycogen and starch must be converted to “usable” energy:

ANIMALS and PLANTS use CELLULAR RESPIRATION to

convert food (NRG) ingested to a form they can use:

ATP-

Adenosine triphosphate

Characteristics of Life

8. Energy Use (cont.)-

• CELLULAR RESPIRATION:

– How food is broken down on a cellular level to produce VIABLE energy.

– 3 stages of Cellular Respiration (later)

– O2 is required for Cellular Respiration to go to completion

Characteristics of Life

Characteristics of Life

8. Energy Use (cont.)-

Animals: Breathe in O2 which moves from the lungs to the blood stream which carries oxygen to all cells so that cellular respiration can occur.

Products of Cell Respiration:

CO2, H20, and ATP

-Water used in other cell processes, CO2 not needed in large quantities, so exhaled.

Characteristics of Life

8. Energy Use (cont.)-

• Plants: Take in CO2 which is used for photosynthesis.

Products of Photosynthesis:O2 and glucose (starch)

-O2 and glucose in turn used in cellular respiration to form ATP, usable NRG

8. Energy Use (cont.)-

SOOO…

Plants convert CO2 to a usable form for animals and animals produce CO2 for plants as a biproduct of cellular respiration.

*Write a short summary demonstrating your knowledge of

this energy cycle*

Characteristics of Life

Characteristics of Life

8. Energy Use (cont.)-

• PLANTS: Energy produced during cellular respiration is used to power photosynthesis

• ANIMALS: Energy produced during cellular respiration is “free” energy that can be used to power all of the processes needed to sustain life.