Science exam review (all terms)

polar

Molecule with partial charges. Mixes with water.

nonpolar

No partial charges. Do not mix with water.

electrons in water

reason for polarity

Covlant bonds

A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms. (strong atraction)

hydrogen bond

weak attraction between a hydrogen atom and another atom

Lipids

Used for long term energy storage, some structure, insulation. Found in cell membrane. No real subunits, but made of glycerol and fatty acids.

Lipids structure

3 glycerol and 1 fatty acid. Function is long term energy storage in a cell.

Lipids function

long term energy storage

real life examples of lipids

fats, oils, waxes, certain vitamins (such as A, D, E and K), hormones and most of the cell membrane that is not made up of protein.

Saturated

Fats with the maximum number of hydrogens.

unsaturated fats

Fats with open spots for hydrogen bonds

Triglycerides

an energy-rich compound made up of a single molecule of glycerol and three molecules of fatty acid.

Phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

composition of lipids

carbon, hydrogen, oxygen

2 parts of lipids

glycerol and fatty acids

What makes phospholipids polar

A single phospholipid molecule has a phosphate group on one end, called the "head," and two side-by-side chains of fatty acids that make up the lipid "tails. " The phosphate group is negatively charged, making the head polar and hydrophilic, or "water loving." The phosphate heads are thus attracted to the water

Hydrophobic

Water fearing

Hydrophilic

water loving

Why do phospholipids form a bilayer?

-the polar heads are hydrophilic so they want to be touching the water, so they arrange themselves on the outside of the bilayer where they can be touching water

-the nonpolar tails are hydrophobic and don't want to touch water, so they arrange themselves on the inside of the bilayer where the heads are between them and water

Proteins in cell membrane

Are the passage ways for material to enter or leave the cell

What can go in and out of the cell membrane

water, carbon dioxide, and oxygen

phospholipid bilayer

A double layer of phospholipids that makes up plasma and organelle membranes.

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

What molecues can move through without proteins?

water, oxygen, carbon dioxide

cell theory

idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells

Hooke

discovered cells

Van Leeuwenhoek

first to observe bacteria

Schleiden

said all plants are made of cells

Scwann

said all animals are made of cells

Remack

said all cells come from pre-existing cells

Virchow

stole Remack's idea (all cells come from other cells)

Orgenelles in animal cells

nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, vesicles, and vacuoles.

Organelles in plant cells

chloroplast, cell wall, plastids, and a large central vacuole plus all the cells in animal cells

Eukaryote

A cell that contains a nucleus and membrane bound organelles

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

animal cell

does not have a cell wall or chloroplast but has a small vacuole

plant cell

contains a cell wall, chloroplast and large vacuole

Ribisomes

makes protiens

Lysosomes

An organelle containing digestive enzymes (cleans the cell)

cell membrane

A cell structure that controls which substances can enter or leave the cell.

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Rough ER

System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm

Smooth ER

An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Golgi Apparatus

A system of membranes that modifies and packages proteins for export by the cell

Vacuoles

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Hypotonic

when comparing two solutions, the solution with the lesser concentration of solutes

Isotonic

Having the same solute concentration as another solution. (same on inside and out)

Homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

Solute

A substance that is dissolved in a solution.

Solvent

A liquid substance capable of dissolving other substances

Biotic

living

aboitic

non living

postitive relationships in the enviroment

result in better growth, reproduction, and survival for at least one species involved in the interaction, without negatively affecting the other species

Negitive relationships in the enviroment

Where two species are harming each other in some way

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected (is not harmed)

Parasitism

relationship where a species is being harmed while the other is benefiting

Mutualism

relationship where both species are benefiting

Competition

Species competing with each other for limited food/resources

Effect of Invasive Species

species are dying/being killed

population growth

increase in the number of people who inhabit a territory or state

density dependent factors

limiting factor that depends on population size

density independent factors

the rate of growth of a population at any instant is limited by something unrelated to the size of the population

carrying capacity

Largest number of individuals of a population that a environment can support

Population crash

fewer children are born, deaths, lack of resources (goes down)

exponential growth

Growth pattern in which the individuals in a population reproduce at a constant rate (looks like a j)

logistic growth

Growth pattern in which a population's growth rate slows or stops following a period of exponential growth (looks like an s)

carnivore

A consumer that eats only animals (meat)

herbivore

A consumer that eats only plants.

omnivore

An animal that eats both plants and animals

Autotroph

An organism that makes its own food (type of producer)

producer

Organism that makes its own food

Heterotroph

An organism that cannot make its own food.

Consumer

An organism that obtains energy by feeding on other organisms

Decomposer

An organism that breaks down wastes and dead organisms

Effect of carnivore increase and decrease

More carnivores = less plants/weaker species. Less carnivores = more plants/weaker species

levels of food pyramid

primary producer, primary consumer, secondary consumer, tertiary consumer

10% rule

The amount of energy passed up to the levels of the food pyramid reduces as you go up. (ex: 1000- 100)

food web

community of organisms where there are several interrelated food chains

food chain

A series of steps in which organisms transfer energy by eating and being eaten

energy pyramid

A diagram that shows the amount of energy that moves from one feeding level to another in a food web

reactants of photosynthesis

carbon dioxide and water

products of photosynthesis

glucose and oxygen

Chemical formula of photosynthesis

6CO2 + 6H2O → C6H12O6 + 6O2

Light Independant Reactions (Calvin Cycle)

chemical reactions that convert carbon dioxide and other compounds into glucose, does not require light (In the Stroma)

light-dependent reactions (Calvin Cycle)

reactions of photosynthesis that use energy from light to produce ATP and NADPH (In the thylakoid membrane)

ADP

(Adenosine Diphosphate) The compound that remains when a phosphate group is removed from ATP, releasing energy

ATP

adenosine triphosphate) main energy source that cells use for most of their work

Light independent steps

1. Light is absorbed at PS2 (The light excites electrons)

2. Electron Transport Chain (Electrons push H+ through the membrane, and into the thylakoid space)

3. Light is absorbed at PS1 (NADPH is created, and used for the Calvin Cycle)

4. ATP Synthase (H+ builds up in the membrane, and ATP Synthase moves them out the stroma)

What happens to carbon in the Calvin Cycle?

It is converted to organic compounds

Carbon cycle

nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again.

nitrogen cycle

The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere

water cycle

the cycle of processes by which water circulates between the earth's oceans, atmosphere, and land, involving precipitation as rain and snow, drainage in streams and rivers, and return to the atmosphere by evaporation and transpiration.

purpose of carbon cycle

Fixes the carbon of our atmosphere (carbon dioxide) into a more usable form (glucose/carbs

purpose of nitrogen cycle

Nitrogen cycling through the various forms in soil determines the amount of nitrogen available for plants to uptake.