SNC 2D5 Biology - Cells

All Living Things

Have a lifespan, grow, respond to their environment, require energy, produce waste.

Diffusion

The movement of particles from an area of high to low concentration.

Concentration

The amount of molecules in a certain volume.

Osmosis

Diffusion except it deals with water.

Semipermeable Membrane

A divider that lets certain substances in and keeps others out.

Osmosis Explained

Water will try to balance the concentration of items in it.

Hypertonic

Cell has less substances dissolved inside, it will try to balance. (Becomes small and shriveled.)

Hypotonic

Cell has more substances dissolved inside, it will try to balance. (Becomes oversized and inflated.)

Isotonic

The amount of substances dissolved inside and outside are the same.

Cell Membrane

A boundary that selects what is allowed in and out.

Lipid Bilayer

Another name for cell membrane, it's made up of two fatty layers.

Hydrophilic Heads

Water loving.

Hydrophobic Tails

Water fearing.

Cytoplasm

Jelly fluid that holds nutrients and waste.

Cytosol

Watery, more liquid component of cytoplasm that dissolves nutrients.

Nucleus

Directs cell's activities, made up of DNA.

DNA

Deoxyribonucleic acid.

Nuclear Membrane

Separates nucleoplasm from cytoplasm.

Nuclear Pores

In the nuclear membrane, selects which large molecule can enter or exit.

Nucleolus

The "mini brain", responsible for the synthesis of ribosomes.

Ribosomes

Little granules of RNA, make protein.

Mitochondria (Power Plant)

Powerhouse of the cell, provides energy for cells.

Endoplasmic Reticulum

A network of tubules that carry materials throughout the cell.

Rough ER (RER)

Is covered in ribosomes. (Makes lots of protein.)

Smooth ER (SER)

Doesn't have ribosomes. (Makes lots of fat.)

Golgi Apparatus

Stores, modifies, and packages proteins from the RER. Also processes and removes waste. (Looks like a stack of flattened membranes.

Cytoskeleton

Protein filaments that are embedded in the cell membrane, help resist physical damage.

Vacuoles

Stores fluids and nutrients. Animals have small ones, plants have large ones.

Vesicles

Used for the transport of wastes and nutrients. (Smaller than the vacuole.)

Lysosomes (Animal Only)

Contain digestive enzymes, fight invading bacteria and accelerate cellular reactions.

Suicide Sacs

(Lysosomes) Destroy themselves when old, called apoptosis.

Cell Wall (Plant Only)

Made of cellulose, protects and supports the cell.

Chloroplast (Plant Only)

Bean-shaped, contains chlorophyll, gives leaves their green colour.

Granum

Full stack of thylakoids.

Stroma

A thick fluid in which chloroplast floats in. (Contains proteins necessary for photosynthesis.)

Thylakoids

Membrane stacks.

The Animal Cell

The Plant Cell

Cell Cycle Beginning

Starts at nucleus.

The nucleus contains _____________________ and _____________________.

Information and instructions.

The information contains: (Nucleus Information)

1. What the cell will become.
2. How it will work.
3. How long it will last.

Chromosomes

Store information. Comes in pairs.

DNA Code

Extremely long strands of molecules (Double Helix)

Composition of DNA

A sugar, a phosphate, and a base.

Types of bases in DNA

Adenine, cytosine, guanine, and thymine.

DNA Base Rule

The number of purine = the number of pyrimidine.

Adenine

Purine.

Cytosine

Pyrimidine.

Guanine

Purine.

Thymine

Pyrimidine.

Adenine and Thymine

Only bond.

Guanine and Cytosine

Only bond.

Bases Composition

Stack on top of each other.

DNA Strands

Genes or genetics.

Genes

Areas of DNA that provide the info necessary to create proteins.

Proteins

Workers of the cell, handle all tasks and functions.

DNA Controls

Everything in your body, how you look, you health, and intolerances to foods.

DNA to Protein

Follows transcription and translation.

RNA

Ribonucleic Acid

Translation

RNA leaves the nucleus, and moves into the cytoplasm. Joins ribosomes which decode using amino acids.

Transcription

Process by which DNA is used as a template to create RNA.

Protein Tasks

Building parts of the body, carrying things through the body, transfer signals, and helps speed up chemical reactions.

Cell Cycle

2 main phases, interphase and cell division. (Begins at the moment of conception, stops at death.)

S Phase

Where DNA is replicated before division. (Synthesis)

G2 Phase

More cell growth and preparation for mitosis.

Cell Division

A parent cell divides into two daughters. Phases being mitosis and cytokinesis.

Cytokinesis

The last part of the division when the cells pinch off.

Why Cells Divide

They are too large, need to repair, maintenance of a function, or growth of the organism.

Mitosis Phases

PMAT (Prophase, Metaphase, Anaphase, Telophase)

Prophase

Nucleus disappears, centrioles separate and move to opposite sides, spindle fibres attach to centrometres. (Plants don't have centrioles)

Metaphase

Nuclear envelope breaks down, centrometres align with fibres, fibres pull them to the equator of the cell.

Anaphase

Fibres contract and shorten, centrometre divides, chromatids pulled to opposite ends.

Telophase

Fibres breakdown and disappear, nuclear membranes re-form, chromatin starts to form, division of nucleus complete.

Cytokinesis Phase

Cytoplasm forms two daughter cells, animals get cleavage furrow and plants get a cell plate between.

Why The Cell Cycle Might Stop (G1)

Not enough nutrients at G1.

Why The Cell Cycle Might Stop (S)

DNA has not replicated.

Why The Cell Cycle Might Stop (G2)

DNA is damaged.

Why The Cell Cycle Might Stop (A)

The DNA has not attached to the spindle fibres and segregated properly.

Cell Death

Cells leave the cycle as they are old, it's normal.

Cell Suicide

Cell is broken down, nutrients are packaged. (Coded DNA)

Cancer

When DNA is damaged and the code is changed. Causes mutation which can allow the cell to ignore stop signs.