Bio Test 1

Matter

anything that takes up space and has mass (solid,liquid,gas)

Elements

Substances that cannot be broken down into simpler substances

How many naturally occurring elements are there?

92

Elements that make up 95% of organisms by weight?

Oxygen

Carbon

Hydrogen

Nitrogen

Phosphorus

Sulfur

Atom

smallest part of an element

Atoms are made up of…

Protons, Neutrons, and Electrons

atomic # is the…

# of protons

mass # is the…

# of protons + the # of neutrons

Isotopes are…

atoms of the same elements w/ different #’s of neutrons

Radioactive isotopes are…

emit various types of energy as they decay (isotopes that release energy)

uses of low level radiation

-diagnostic radiation

-PET scan

Uses of high level radiation…

-kill bacteria+fungi

-can be used to kill cancer cells

-radioactive dating (see how old trees are)

-DNA replication

Electrons have what charge?

Negative charge

Neutrons have what charge?

Neutral charge

Protons have what charge?

Positive charge

How many atoms can the electron shell closest to the nucleus hold?

Only 2

How many atoms can the shell after the first one hold?

8

What is the valence shell?

The outermost shell

What is the octet rule?

Having 8 electrons

What is the valence shell?

The outermost shell

When is the valence shell electronically stable?

When there are 8 electrons, octet rule

What is the atoms valance?

The amount of space left for electrons

if only 6 electrons in the outermost shell them how many electrons are needed for the atoms valance?

2, to make 8

What are the 2 principles that atoms behave according too?

they are inactive, they are intert (not reactive, no more space)

Molecules are when blank or more atoms bond together.

2

Compounds are when blank or more different blanks bond together.

2, elements

What is the difference between a pure element and a molecule?

Pure element is a substance made of only 1 type of atom, but a molecule is a group of 2 or more atoms chemically bonded together.

The 3 types of bonds are…

-ionic

-covalent

-metallic

An ionic bond is when…

atoms gain or lose electrons to fill the outermost shell (valence shell), after it gains or loses an electron, it becomes an ion.

A single covalent bond is when…

…you share 1 pair of electrons

-Double covalent-sharing 2

-Triple covalent-sharing 2 ect.

What shape are molecules?

3 dimensional

Explain a non-polar covalent bond…

when 2 atoms share electrons equally

Explain a polar covalent bond…

when 2 atoms share electrons but not equally

What type of bond is a hydrogen bond?

It's a weak bond that is weak individually but strong collectively.

Why is water so special?

-Water has unusual properties essential to life

-the first cells evolved in water

-organisms are composed of 70-90% water

Is water a polar or non-polar molecule?

Water is a polar molecule because it has positive and negative charged bonds.

To heat water the amount of energy needed is called a …

Calorie

Water has a high heat capacity, what does this mean?

This means it takes a lot of energy to heat it up but it holds onto the heat for a long time.

Why does sweat cool us down?

Because water has a high heat of vaporization; when we sweat, the water evaporates off our skin, cooling us down its called evaporative cooling

Why is water an excellent solvant?

Because a lot of things can be dissolved in it; aqueous solution

Hydrophilic…

molecules attract water; water loving/dissolving

Hydrophobic…

molecules do not attract water; water fearing/non-disolvable

If you mix water and sugar together, what is the solvent, solute, and solution in this example?

Solvent=water

Solute=sugar

Solution=sugar water

Cohesion is when the tendency of water molecules to stick together, but it doesn’t have to be just water. Why does this happen?

It happens because of the attraction of molecules, (+)/(-)

Adhesion is when water sticks to everything else. Why does this happen?

It happens because the tendency of polar molecules to stick to other molecules

Why does water have a high surface tension?

Because the hydrogen bonds are holding it together

Why does ice float?

Because it is less dense than water

How do bodies of water freeze and why is it important?

Top-down, because when the top layer freezes, it creates a layer of insulation that keeps the organisms below alive.

Acid solutions- Blank are greater than blank

hydrogens, hydroxide

Base solutions- Blank are greater than blank

hydroxide/hydrogens

What pH does water have?

7 pH

Is pH of 7 acidic or a base?

It is neutral

Anything less than a pH of 7 is? 1-7

acidic

Anything greater than 7 is? 7-14

Base

What is a buffer?

Something that helps keep the pH of a certain thing stable

Why are bicarbonate ions so important?

They are like buffers and help keep things from getting to acidic or base.

Human blood has a pH of?

7.4, anything higher, and the cells will die

What is a virus?

An obligate parasite (it cannot reproduce on its own, only w/ a host cell)

What are viruses made of?

A protein coat and bacteria

True or false: A bacteria is smaller than a virus?

False, a virus is smaller than a bacteria

List 3 shapes a virus comes in:

-Helix

-Sphere

-Polyhedron

Viruses are infectious agents. What does that mean?

They affect almost every type of organism on earth

Do bacteriophages infect bacteria or viruses?

Bacteria, some infect only plants, animals, humans

Bacteriophages is a virus that ONLY infects bacteria, true or false?

True

What are some examples of viruses that are tissue or cell specific…

Pneumonia-respiratory system

Herpes virus-mouth/genital area tissue

Cold virus- respiratory

What are the 6 steps for the reproductive cycle of a typical enveloped animal RNA virus?

1. Attachment

2. Entry

3. Replication

4. Biosynthesis

5. Assembly

6. Budding

What does latency mean and give an example

a virus that lays dormant can be for months or years, an example could be the herpes virus

What is a prion?

Proteins that infect the nervous system

Why do prions get dangerous?

We have proteins in our brain, but sometimes the proteins’ shape changes and becomes an abnormal prion shape. When it changes its shape, it changes its function. The abnormal protein shape causes other proteins to turn abnormal also. Prion diseases are fatal 100% of the time.

Scrapie is found in what animal?

Sheep

Bovine spongiform encephalopathy is what?

Mad cow disease, found in cattle but can be passed to people

Creutzfeldt-Jakob disease is found in?

Humans

Kure is found in?

canibalism, human to human, tribe story

How do we get prion diseases?

We get prion diseases from eating food that has infected tissue

What is the function of the plasma membrane?

Keeps whats in the cell in and whats outside out

What is the function of cytosal?

Makes up the cytoplasm(fluid in cell), holds genetic material like DNA

2 different types of cells are:

-Prokaryotic

-Eukaryotic

What is a prokaryotic cell?

a unicellular cell

2 groups(bacteria +archea)

-lacks nuclear envelope

-lacks a membrane-bound nucleus, they have DNA but no membrane, so DNA floats around in the cytoplasm.

What are the 4 main groups of a Eukaryotic cell?

-Plant cells

-Animal cells

-Fungi

-Protis

What is a Eukaryotic cells?

can be unicellular(1) or multicellular

-They have a true nucleus surrounded by nuclear envelope or membrane

Explain the cell theory:

-All organisms come from 1 or more cells

-Cells are the basic living unit of structure and function in organisms

-All cells come only from other cells

Why is it good that cells are small? (3 reasons)

-They rely on diffusion, osmosis, and active transport to bring nutrients to the cell and to get rid of waste

-Cells are also small, so the nutrients can get to the whole cell

-Cells are small for diffusion

Is bacteria or archea stronger and why?

Archea are stronger, both can be found in harsh environments, but archeae are extremophiles, they can live in unique, very harsh environments

What are the 3 basic shapes of prokaryotic cells?

-Bacillus-rod-like

-Coccus-Sphere

-Spirilla-spirals

When talking about bacteria and sickness, we can know the type of bacteria based on the name, why is this?

Because the bacteria's shape is often in the sickness name. ie. streptococcus

What organelles make up the cell envelope?

-cell wall

-plasma membrane

capsule

What is the cell walls function?

-protection

-maintain shape of bacteria

-2 outermost layer

What is the function of the capsule?

-gelatinis sheet, outside coating also called clicocallics

-sticky layer(will stick to stuff, ex. teeth bacteria)

-keeps bacteria from drying out

-protective layer, bacteria with a capsule can protect themselves against antibiotics bc the antibiotic cannot penetrate into the inside to kill it.

What is the purpose of a flagellum?

Allows movement of the organism in its environment (sperm-tail)

What is the Fimbrie?

short appendages some bacteria has, used to attach to surfaces

Congigation pillie is the…

reproductive, asexual reproduction precursor, swaps genetic material