Unit 2 - cells and tissue

Cells are

Basic unit of life

Nucleus

Contains DNA of the cell and directs the cell's functions

Cytoplasm

Fluid inside cells that contains all of the organelles

Cytoskeleton

Forms a supportive framework in the cytoplasm (like the human skeleton) - 3 different kinds

Cell Membrane

Made of Phospholipids which are constantly moving

-Selectively Permeable

selectively permeable

Actively functions in order to control what enters and leaves the cell

Phospholipids

Bilayer - Heads like water but tails don't like water

Intracellular fluid

Cytoplasm - on the inside

Extracellular Fluid

On the outside, all throughout the body, keeps homeostasis

Ribosomes

Read RNA and make amino acids

Endoplasmic Reticulum

Takes the amino acids and makes them into proteins

Proteins are made up of

amino acids

Golgi Apparatus

proteins are then modified, packaged, and shipped to where they are needed

Mitochondria

makes energy and is the powerhouse of the cell

Lysosomes

Garbage disposals of the cell

Chemical Reactions

Break down food so we can get the energy out of it

Metabolism

all of the reactions that occur in living organisms

High Metabolism

your body reactions occur fast, thus breaking things (food) down quickly

Low Metabolism

your body reactions occur slower, thus breaking things (food) down much slower

Atoms

Smallest unit of matter, make up everything

Molecules

2 or more atoms that combine - also called a compound

Ions are

A charged atom - positive or negative charge

Examples of ions/electrolytes

Na+ - Sodium

K+ - Potassium

Cl- - Chloride Ca2+ - Calcium

Kidneys do what to help what?

Kidneys work to keep your electrolyte balance constant (homeostasis).

Organic Compounds

Have carbon in them

Carbohydrates, fats, proteins, and nucleic acids

Inorganic Compounds

Water, salt, oxygen, carbon dioxide

Carbohydrates - organic

provide energy and there are two main types - simple and complex carbohydrates

simple carbohydrates

Sugars - easy fro your body to break down

Candy, cereal, etc

complex carbohydrates

Fibers, starches, pasta, bread, rice, etc.

Fats - organic

More energy that carbs, used to insulation - three types

Saturated

bad fat that leads to heart disease

Butter, lard, animal fat

Unsaturated fat

good fat - olive oil, peanut oil, canola oil

Trans fats

bad fat

Proteins

-Provide energy, make enzymes, structural units, hormones

-makes up hemoglobin and myoglobin which carry oxygen

-Made up of amino acids

Stem Cell

The first cells after fertilization (sperm and egg coming together) are stem cells - job is not determined yet

Differentiation

When a cell gradually changes into a particular cell type

Embryonic stem cells

First 6 days: Totipotent: can potentially turn into any kind of cell

Day 7 - 8 week: Pluripotent: can potentially turn into most kinds of cells

Adult (Somatic) Stem cells

Found in fully developed humans (infants and children too)

Multipotent: Has limited range of cells it can turn into

induced pluripotent stem cells

Body cells already differentiated are changed back into pluripotent stem cells

- New technology

- Little to no success

Differentiate

To undergo a specific cellular change to become a more specialized cell

Progenitor cells

are "committed" to becoming a certain type of cell

Different cells means

different functions

Different types of tissues

tissue is made up of cells with the same function, and can be distinguished by cell size, shape, organization, and function

4 major types of tissues in the human body

epithelial, connective, muscle, nervous

Amino acids

organic compounds that combine to make proteins

Electrolytes

A chemical compound (like salt) that dissolves in body fluids to release charged particles. It represents the overall substance before or after it dissolves.

Ions

An individual atom or molecule that carries a positive or negative electrical charge (NA+ for ex) It is the active particle that actually does the work in the body.

Relationship between electrolytes and ions

Electrolytes are the source, and ions are the result. When you consume an electrolyte, it dissolves in body water and breaks apart into individual, charged ions.

Epithelial vs. Connective tissue

Epithelial is made up of ONLY cells, connective tissue is mainly a matrix that is made from a cell

Adipose

connective tissue that stores fat and gets larger as more fat gets accumulated, it is found all around the body and it cushions joints, insulates/stores energy and the amount one has is affected by calorie intake

Progenitor cells

biological cells that descend from stem cells and can divide to create specialized, mature cell types

Collagen fibers:

thick threads of protein collagen which are the major structural protein of the body; long, parallel bundles, resists considerable pulling force

Elastic fibers:

weaker than collagenous fibers but elastic; common in places subjected to stretching (such as vocal cords)

What does adipose connective tissue look like?

closely packed empty looking bubbles

What does loose (areolar) connective tissue look like?

Sparse open framework and gel-like background

What does loose (reticular) connective tissue look like?

Delicate, dark branching network

What does dense regular tissue look like?

Uniform, parallel waves of thick pink fibers

What does dense irregular tissue look like?

Chaotic, interwoven mat of thick fibers

What does cartilage tissue look like?

Smooth, firm matrix with cells tucked into small pockets