Biology Midterm Prep

The study guide for 9th grade bio. (Mrs. Z's class)

hypothesis

An educated guess made before research is done

theory

A hypothesis that has been tested with a significant amount of data. An educated guess backed up by data.

Linnaeus

father of taxonomy and binomial nomenclature

binomial nomenclature

Classification system in which each species is assigned a two-part scientific name: Genus species

Correctly list the levels of biological organization.

Kingdom, phylum, class, order, family, genus, species

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

non polar covalent bond

equal sharing of electrons

polar covalent bond

unequal sharing of electrons (ex. water)

How do water molecules bond?

hydrogen bond: slightly negative oxygen bond to slightly positive hydrogen.

Cohesion

water molecules sticking to each other

Adhesion

water molecules sticking to other surfaces

surface tension

because of cohesive nature (due to hydrogen bonding) of its molecules water molecules resist external forces: the property that allows certain bugs to walk on water

capillary action

tendency of water to rise or get pulled up due to cohesion/adhesion: water moving up a plant stem

solute

the substance that is dissolved

solvent

the substance in which the solute dissolves

solution

a mixture that forms when one substance dissolves another

organic compounds

compounds that contain carbon

What's is the significance of carbon?

It's found in all living things and essential to life on earth.

CHONPS

carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur

glycogen

storage form of glucose in animals

starch

storage form of glucose in plants

Cellulose

storage form of glucose in cell walls

saturated fatty acid

a fatty acid chain with single hydrogen bonds: solid at room temp

unsaturated fatty acid

a fatty acid chain with double hydrogen bonds: liquid at room temp.

phospholipids

a lipid containing a phosphate group in its molecule: polar head and nonpolar tail

carb monomer

monosaccharide

carb polymer

polysaccharide

carb function

short term energy storage and structure

protein monomer

amino acids

protein polymer

polypeptide

protein function

structure, communication, membrane transport, catalysis, recognition and protection, movement, cell adhesion

lipid monomer

fatty acid

lipid function

long term energy storage and insulation

nucleic acid monomer

nucleotide

nucleic acid polymer

DNA and RNA

nucleic acid function

store and transmit genetic info

Why are cells so small?

smaller cells have more surface area making it easier to pass oxygen, nutrients and waste materials

cell theory

idea that;
1. all living things are composed of cells
2. cells are the basic units of structure and function in living things
3. new cells are produced from existing cells

nucleus

control center of the cell

cell wall

strong, supporting layer around the cell membrane in plant cells

golgi body

structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell: UPS of the cell

ribosomes

makes proteins

endoplasmic reticulum

a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another (highway system of the cell)

mitochondria

powerhouse of the cell

chloroplast

site of photosynthesis

cytoskeleton

strength and support, movement of cellular structures and materials

vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

plasma membrane

selectively-permeable phospholipid bilayer forming the boundary of the cells

fluid mosaic model

properties of phospholipid bilayer

1. determines passive
permeability of
membranes (diffusion)
2. lipid soluble
molecules permeate or
diffuse through
phospholipid bilayer easily
3. water soluble (hydrophilic)
molecules do not
4. allows small polar molecules in

diffusion

the process by which molecules move from an area of higher concentration to an area of lower concentration

facillitated diffusion

process that moves materials from high to low concentration with the help of protein channels; does not require energy

osmosis

diffusion of water

active transport

the movement of materials through a cell membrane using energy

selectively permeable membrane

membrane that allows some substances to pass more easily than others and blocks the passage of some substances altogether

hypotonic solution

a solution in which the concentration of solutes is less than that of the cell that resides in the solution (more water)

hypertonic solution

a solution in which the concentration of solutes is greater than that of the cell that resides in the solution (less water)

isotonic solution

a solution whose solute concentration is equal to the solute concentration inside a cell

What organic molecules are enzymes made of?

proteins

What do enzymes do?

speed up chemical reactions and lower activation energy: they catalyze reactions, not start them

ATP

adenosine triphosphate, energy used in cell

ATP vs ADP

ATP has 3 phosphate groups (more energy) and ADP has two phosphate groups.

Leaf Layer Diagram

Chloroplast Diagram

also includes strands of DNA and ribosomes: proof of endosymbiotic theory

What is the relationship between location of chloroplasts in the leaf and photosynthesis?

The mesophyll palisade has more chloroplasts allowing for more photosynthesis. This layer is closer to the top of the cell.

Cuticle

the waxy, waterproof layer that covers the leaves and stems of most plants.

mesophyll

the tissue in the interior of the leaf

spongy mesophyll

- layer of loose tissue found beneath the palisade mesophyll in a leaf
- less photosynthesis is done here (less chloroplasts)
- air pockets allow for respiration

palisade mesophyll

- layer of tightly packed cells under the upper epidermis of a leaf
- more photosynthesis is done here (morechloroplasts)

gaurd cells and stomata

pairs of cells that surround stomata and control oppening and closing

epidermis

a tissue made up of a single layer of cells which covers the top and bottom of a leaf

thylakoid

a flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy: light dependent reaction done here

granum

stack of thylakoids

What colors are
- chlorophyll a
- chlorophyll b
- xanthophyll
- carotene
- anthocyanin

- chlorophyll a: blue-green
- chlorophyll b: yellow-green
- xanthophyll: yellow
- carotene: yellow to orange
- anthocyanin: blue, red, purple

Why do leaves change color in the fall?

The chlorophyll breaks down, the green color disappears, and the yellow to orange colors become visible.

equation for photosynthesis

6CO2 (carbon dioxide)+ 6H2O (water) + energy = C6H12O6 (glucose) + 6O2 (oxygen)

What factors affect photosynthesis?

1. temperature
2. light intensity
3. the availability of water.

Calvin Cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars

Light Dependent Reaction

reactions of photosynthesis that use energy from light to produce ATP and NADPH