Mini Review

A2.2.1, A2.2.7

Cell

The smartest unit that can carry out the processes of life (MR.HGREN)

Cell Theory

1) All living organisms are composed of one or more cells.

2) The cell is the basic unit of structure and function in all organisms.

3) New cells arise only from the division of pre-existing cells. (cell division)

Organisms can be:

• Unicellular- One cell does anything needed for life (bacteria)

• Multicellular- Many cells working together (humans and trees)

Unicellular organisms

Organisms that carry out all the functions of life inside just one cell. This means a single cell must perform every process needed to stay alive, respond to its environment, and reproduce.

Key functions (MR.HGREN)

• Metabolism

• Reproduction

• Homestasis

• Growth

• Response'

• Excretion

• Nutrition

Osmosis

Net movement of water across a partially permeable membrane from higher to lower water potential

Diffusion

Net movement of particles from higher to lower concentration

Catabolism

Breaking down molecules to release energy

Anabolism

Building larger molecules for growth and repair

Paramecium

Heterotrophic nutrition + movement by cilia

Heterotroph

An organism that obtains energy and nutrients by consuming other organic matter

Chlamydomonas

Autotrophic nutrition + movement by flagella

Autotroph

Makes its own glucose by photosynthesis using chloroplasts

Eukaryote

A cell with nucleus and other membrane bound organelles (plant, animals, fungi, protists)

Organelle

A specialized structure inside a cell that performs a particular function.

Cytoplasm

Jelly-like interior outside the nucleus where many reactions and organelles are found.

Plasma membrane

A thin, flexible boundary that surrounds the cell and controls exchange with the environment.

Nucleus

Stores DNA and controls gene expression

Mitochondria

Powerhouse of the cell, produces ATP

Rough ER

Has ribosomes; synthesis proteins for secretion or membranes

Smooth ER

Lipid synthesis, detoxification, and Ca2 + storage

Golgi apparatus

Modifies and packages proteins/lipids into vesicles for delivery

Lysosome

Enzyme-filled vesicle for digestion and recycling

80S Ribosomes

Large ribosomes in eukaryotes that translate mRNA into protein.

Nucleus

A double-membrane organelle containing the cell’s DNA as linear chromosomes.

Vesicle

A small membrane-bound sac used for transport or storage inside cells

3 fundamental structures

1. DNA

2. Cytoplasm

3. Plasma Membrane

3 problems every cell must solve

• Store information

• Enable metabolism

• Create boundaries

DNA

A double stranded molecule that stores genetic information

In Eukaryotes DNA is mainly stored in…

Nucleus