Honors Biology - Midterm Review

Steps of the scientific method

1) Observe and ask questions

2) Infer answer (hypothesis)

3) Design controlled experiment to test hypothesis

4) Collect and analyze data

5) Make conclusion

Controlled Variable

Factor that is kept the same to ensure that the test is not influenced by any other factors

Independent Variable

The factor that changes in the test

Dependent Variable

What is measured from the change of the independent variable

What is a controlled experiment

Test where only one factor is changed

Main components of controlled experiment

1) Independent variable

2) Dependent variable

3) Control group

What is a theory

Related hypotheses tied together and backed by many studies

8 Characteristics of living things

1) Made of at least one cell

2) Have a genetic code written in DNA

3) Can obtain and use materials and energy

4) Can grow and develop

5) Can reproduce

6) Can respond to its environment

7) Can maintain a stable internal environment

8) Can change over time (evolution)

Polarity

If electrons are shared equally or unequally between atoms

Why is water a polar molecule

Electrons are shared unequally

Atomic Mass

Protons + neutrons (mass of nucleus)

Atomic Number

Number of protons

What can never change without changing the element

Atomic number

What is an ion

When atom gain or lose electrons, ions are created

Example of an ion

Sodium ion (Na+)

A positive ion results when an atom _____________ an electron(s)

Loses

Weakest type of bond

Hydrogen Bonds

Ionic bond

Attraction between ions of opposite charge

Covalent bonds

When two atoms share one or more pairs of outer shell electrons

Molecule

Smallest unit of most compounds

Compound

Substance formed by 2 or more elements in a fixed ratio

Solvent

Dissolves other substances

Solute

Dissolved substance

Acid

Compound that produces H+ ions in solution

Base

Compound that produces OH- (hydroxide) ions in solutions

Hydrolysis is a __________ process

breaking

Dehydration synthesis is a _______________ process

building

Process to turn 2 monosaccharides into a disaccharide

Dehydration synthesis

Break disaccharide into 2 monosaccharides

Hydrolysis

Organic compounds must contain which element

Carbon

What are the four major biological compounds in living things

1) Carbohydrates

2) Lipids

3) Proteins

4) Nucleic acids

Monomer of carbohydrates

Monosaccharide

Monomer of lipids

Fatty acids

Monomers of nucleic acids

Nucleotide

Monomer of proteins

Amino acids

Function of monosaccharides

Animal’s main energy source

Function of fatty acids

Reserve energy-storage molecules

Function of nucleotides

Store and transmit genetic infromation

Function of amino acids

Repair, growth and enzyme activity

What are enzymes

Catalysts that speed up chemical reactions by lowering activation energy

Why are enzymes important in living things

Lowers activation energy of chemical reactions and regulate metabolic pathways

5 scientists that helped to form the cell theory

R. Hooke, A. Leewekhoek, M. Schleiden, T. Schwann, and R. Virchow

What did Hooke do

Created the term “cell” by looking at cork slices or cell wall remains of plants

Leewekhoek what did he do

Observed pond water and saw many living things

Schleiden what did he do

Stated all plants are made of cells

What did Schwann do

All animals are made up of cells

Virchow what did he do

New cells came from the division of existing cells

3 types of microscopes

1) Light

2) Scanning EM

3) Transmission EM

What do light microscopes do

Uses light to see shape and structure of cell

What do scanning EM do

Use electrons to see surface structure

What do transmission EM do

Uses electrons to see the inside details of a cell

Prokaryote

• Smallest cell in nature

• DNA in cytoplasm

• Ribosomes are only organelle

• Bacteria

Eukaryote

• Larger and more complex

• DNA in nuclear envelope

• A lot of organelles

• Protist, fungi, animals, plants

Mitochondria

• Plants and animal cells

• Food → ATP during cell respiration

• Contains own DNA

Chloroplast

• Plant cell (algae)

• Photosynthesis

• Chlorophyll (capture solar energy)

• Contains own DNA

Ribosomes

• Plant and animal cell

• Protein beads wrapped in RNA

• Make peptide bonds

• Make lots of proteins

Nucleus

• Plant and animal

• Store genetic info

• Cell division

Nucleolus

• Plant and animal

• Inside nucleus

• Make ribosome

Plastids

• Plants (algae)

• Energy production (chloroplast)

• Storage of nutrients (leucoplasts)

• Pigmentation (chromoplasts)

Vacuole

• Plant and animal

• Membrane pouches to store

  • Waste

  • Water

  • Pigments

  • Food

  • Salt

• Plants have 1 large

• Animals have many

• Paramecia have “contractile vacuole”

  • Pump out excess water

Cell wall

• Plants, bacteria, fungi

• Gives cell shape and protection

• In plants - made of cellulose

Cell membrane

• In all cells

• Determines what enters/exists

• Selectively permeable “gate keeper”

• 2 layers of phospholipids

  • Hydrophilic head

  • Hydrophobic tail

Smooth endoplasmic reticulum

• Plants and animal

• No ribosomes attached

• Enzymes to

  • Synthesize lipids

  • Detoxify a cell

Rough endoplasmic reticulum

• Plant and animal

• Ribosomes on outside surface

  • Make proteins

  • Push into rough ER

  • Transport to golgi

Golgi body

• Plant and animal

• Proteins from ER → modification, sorting, and packaging

• Final product either stays in cell or fuses with cell membrane and contents are released out

Cilia

• Animal

• Cell movement

• Small and numerous

• Hair-like

• Uses energy to cause whip motion in microtubules

Flagella

• Animal

• Long and few

• Whip-like

• Uses energy to cause whip motion in microtubules

Centrioles

• Animal

• Make spindle fibers

  • Split chromosome pairs during cell division

Lysosomes

• Plant and animal

• Filled with enzymes

• Destroy cell products

• Break down fat, carbs, and lipids

• Destroy old/worn-out organelles

Factors that limit size of cell

Surface area and volume

What increases at a faster rate, surface area or volume

Volume

Main components of cell membrane

2 layers of phospholipids and scattered proteins

Diffusion

Movement of molecules from high → low concentration

Facilitated diffusion

H → L

Use of protein channels

Passive transport

Osmosis

Diffusion of water

Passive transport

Hypertonic

Solution high in solute

Cell shrink

Hypotonic

Solution is low in solute

Cell grow

Isotonic

Solution is at equilibrium

Cell stay the same

Plasmolysis

Cell shrinking

Cytolysis

Cell swelling and bursting

Turgor pressure

water pressure inside a plant cell

Semi-permeable membrane

Membrane that allows certain material to pass through

Equilibrium

Balance within a system

Phagocytosis

Cell eating

Cells engulf and destroy foreign particles and dead cells

Active transport

Active transport

Uses energy to move item from L→H (against/up the concentration gradient)

Endocytosis

Cell membrane folds inwards, brings items in

Active transport

Pinocytosis

Cell drinking

Packets of fluid brought inside cell

Active transport

Exocytosis

Materials are released from the cell

Active transport

What process consumes food to make energy

Respiration

What process consumes energy for food

Photosynthesis

Ingredients of photosynthesis

CO₂, H₂O, and sunlight

Products of photosynthesis

C₆H₁₂O₆ (glucose) and O₂

Ingredients of respiration

C₆H₁₂O₆ (glucose) and O₂

Products of respiration

CO₂, H₂O, and ATP

Gas consumed by photosynthesis

CO₂

Gas consumed by respiration

O₂

Gas released by photosynthesis

O₂

Gas released by respiration

CO₂

1st step of photosynthesis

Light reaction

2nd step of photosynthesis

Dark reaction