Honors Biology - final study guide

• What is biology?

• Biology is the study of living things such as plants, animals, and how their bodies work. It helps us understand life and how organisms interact with each other and their environment.

• What are the characteristics of all living things?

• Cellular organization

• metabolism,

• growth and development

• reproduction

• response to stimuli

• homeostasis

• heredity

• evolutionary adaptation 

• What are the 4 organic compounds and monomers (building blocks)?

1. Carbohydrates (Monomers: Monosacchardies)

2. Proteins (Monomers: Amino acids)

3. Lipids (Not made of monomers)

4. Nucleic Acids (Monomers: Nucleotides)

Carbohydrate examples

• Glucose 

• Starch

• Glycogen

• Cellulose 

Proteins examples

• Enzymes

• Hemoglobin 

• Collagen

• Insulin 

Lipids example

• fats and oils

• phospholipids

Nucleic Acids

• DNA

• RNA

Importance of carbohydrates

Provides quick energy for cells and serve as energy storage 

Importance of proteins

Perform a wide range of functions including speeding up chemical reactions, providing structural support, transporting molecules, and regulating body processes 

Importance of lipids

store long-term energy, make up cell membranes, and act as signaling molecules

Importance of nucleic acids

Stores and transmits genetic information and helps make proteins which are essential for all life processes.

What elements do all organic compounds contain?

Carbon

Water is polar in nature. What does polar mean?

Polar means the molecule has a both positive and negative charge, allowing it to dissolve many substances and form hydrogen bonds.

What type of bonds hold a single water molecule together?

• Single molecule = covalent bonds

What type of bonds hold water to other water molecules?

Hydrogen bonds

Cohesion

• Water molecules stick to each other because of hydrogen bonding

• Helps water form droplets and allows it to move as a continuous column in plants

Adhesion

• Water molecules stick to other substances because of their polarity, helping water climb up surfaces

Surface tension

• Water molecules at the surface are pulled tightly together, creating a skin that allows small insects to walk on water or water to form droplets 

High Specific Heat

• Water can absorb or release a lot of heat without changing temperature much

• Helps regulate temperatures in the environment and in living organisms 

Density

• Water is most dense as a liquid at 4°C

• When it freezes, it becomes less dense and ice floats 

Capillary Action

• Water can move upward through narrow tubes against gravity due to the combined effects of cohesion and adhesion

• Essential for transporting water in plants from roots to leaves 

Unique properties of water

• cohesion

• adhesion

• surface tension

• high specific heat

• density

• capillary action

pH scale range

1-14

pH of Acids

less than 7

pH of bases

greater than 7

pH of neutral substance

7

What is a buffer?

A buffer is a substance that helps maintain a stable pH, even when small amounts of acid or base are added

What are enzymes?

a special type of protein that helps speed up in living things

What are catalysts?

a substance that speeds up a chemical reaction without being used up or changed permanently

How do enzymes and catalysts relate to lock and key?

• Just like a specific key fits into a specific lock, only the right substrate fits into the enzyme’s active site 

• only then can it be catalyzed

What does denature mean?

• To dentaure and enzyme means to change its shape, especially its active site, so it can no longer function properly

What factors can cause enzymes to denature?

• High temperature

• Extreme pH levels

• Chemicals 

What is negative feedback?

• A response that reverses a change to bring the system back to normal

• Goal: maintain stability

• Most common in the body

• Example: if you’re too hot, your body sweats to cool down

What is positive feedback?

• A response that amplifies or increases the change, pushing the system further in the same direction

• Goal: achieve a specific outcome quickly

• Less common, but more important

• Example: hormones cause stronger contractions, which trigger more hormones, until the baby is born

General prokaryotic cell characteristics

• No nucleus 

• No membrane-bound organelles

• Small size

• Cell wall

• Plasma membrane

• Ribosomes 

• Cytoplasm

general eukaryotic cell characteristics

• Nucelus 

• Has membrane-bound organelles 

  • Mitochondria

  • ER

  • Golgi apparatus

  • Lysosomes

  • Chloroplasts 

• Larger size

• Plasma membrane 

• Cytoplasm

• May have a cell wall

What structures are found in a prokaryotic and eukaryotic cell?

• Cell membrane 

• Cytoplasm

• Ribosomes

• DNA

• Cell wall

Nucleus

• plants and animals

• contains DNA

Mitochondria

• plants and animals

• energy production

Cell membrane

• plants and animals

• controls what leaves/enters the cell

Cell wall

• plants only

• provides extra support in structure of the plant

Chloroplasts

• plants only

• captures sunlight in photosynthesis

large vacuole

• plants only

• water storage in plants

small vacuole

• animals only

• waste management

Ribosomes

• plants and animals

• makes proteins

Endoreticulum (smooth and rough)

• plants and animals

• builds and transports materials

Golgi apparatus

• plants and animals

• packages proteins

Lysosomes

• plants and animals

• breaks down waste

Centrioles

• animal cells

• important in cell division (mitosis)

Identify the organization of a multicellular organism. (Cells to Organisms)

• Cells → Tissues → Organs →Organ systems → Organisms 

Cell membrane function

• Controls what enters and leaves the cell

• Protects and supports the cell

Nucleus function

• Stores the cell’s DNA

• Controls all cell activities 

Ribosomes function

• Make proteins by assembling amino acids 

• Found either floating in cytoplsm or attached to ER

Mitochondria function

• Produce energy (ATP) through cellular respiration

• Known as the “powerhouse” of the cell

Chloroplast function

• Carries out photosynthesis 

• Contain green pigment called chlorophyll 

Centriole function

• Helps with cell division by organizing the spindle fibers 

• Is the cell membrane impermeable, permeable or selectively permeable?

• Selectively permeable (it allows some substances to pass through while blocking others)

• Explain the role of protein channels in transport

• Allows specific substances that can’t easily cross the lipid membrane to move through

• This transport can be passive (no energy needed)

Equilibrium

• when the concentration of molecules is the same throughout a space

Diffusion

the movement of molecules from an area of higher concentration to lower concentration until equilibrium is reached

Osmosis

• a special type of diffusion involving water molecules moving across a selective permeable membrane from an area of low solute concentration to high solute concentration

Hypotonic

• The solution has lower solute concentration than inside the cell

• Water moves into the cell by osmosis

• Result- cell swells  

Hypertonic solution:

• The solution has higher solute concentration than inside the cell

• Water moves out the cell by osmosis 

• Result- cell shrinks

Isotonic solution:

• The solution has equal solute concentration as inside the cell

• Water moves in and out at equal rates 

• Result- cell stays the same size

What is cytolysis?

When a cell swells and bursts because too much water has entered it 

Active Transport

• Moves molecules from low → high concentration

• Requires energy

• Uses protein pumps or carriers in the membrane 

Passive Transport

• Moves molecules from high → low concentration 

• Does not require energy

Endocytosis

• The cell takes in large molecules or particles by engulfing them

• The cell membrane folds inward to form a vesicle that brings the material inside 

Exocytosis

• The cell releases large molecules or waste by sending out vesicles that fuse with the membrane

• Vesicles carry the material to the cell surface and expel it outside 

Phagocytosis:

• The cell engulfs large particles or even whole cells

• The membrane around the particle, forming a large vesicle called a phagosome

Pinocytosis

• The cell takes in fluids and dissolved small molecules

• The membrane folds inward to form tiny vesicles filled with liquid 

What is the equation for photosynthesis (in symbols and words)?

• 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂

• Carbon dioxide + water + light energy → glucose + Oxygen

What factors affect the rate of photosynthesis?

1. Temperature

2. Carbon dioxide concentration

3. Water availability 

4. Chlorophyll levels 

What is the green pigment found in plants?

• Chlorophyll 

• What types of organisms carry out photosynthesis?

plants

What products are created from photosynthesis?

Glucose (C₆H₁₂O₆) and oxygen (O₂)

Guard Cells

• Location: on either side of the stomata, in the lower epidermis of leaves

• Function: open and close the stomata to control gas exchange

Stroma

• Location: the fluid-filled space inside the chloroplast but outside the thylakoids

• Function: site of the calvin cycle (light-independent reactions) where glucose is made 

Thylakoid

• Location: inside the chloroplast, stacked into structres called grana

• Function: site of the light-dependent reactions where sunlight is captures and ATP/NADPH are produced

Chlorophyll

• Location: inside the membranes of thylakids in the chloroplast

• Function: pigment that absorbed sunlight, especiall blue and red light, to power photosynthesis 

Stomata

• Location: tiny pores on the underside of leaves

• Function: allow gas exchange 

• Give the equation for cellular respiration (in symbols and letters).

• C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP

• Glucose + oxygen → carbon dioxide + water 

• What types of organisms carry out cellular respiration?

All living organisms 

What is the byproduct (waste product) given off in cellular respiration?

• Carbon dioxide and water 

Aerobic Respiration

• Requires oxygen and produces more ATP (around 36-38 ATP)

Anaerobic Respiration

• Does not require oxygen and produces less ATP (Around 2 ATP)

Lactic acid Fermentation

End product: lactic acid (occurs in muslce cells during intense excersize)

Alcoholic Fermentation

• End products: alcohol and carbon dioxide 

• What is the MAIN energy molecule used by cells? How is that energy released from this molecule?

• ATP

• Energy is released when ATP breaks a bond and loses one phosphate group, becoming ADP

What is the other energy carrier molecule that we briefly discussed?

NADH

• How do cellular respiration and photosynthesis affect the carbon cycle?

• Cellular respiration releases that carbon dioxide back into the atmosphere by breaking down glucose

• Photoynstheis removes carbon dioxide from the atmosphere and stores it in glucose 

Explain binary fission and the structure of DNA in prokaryotes.

• Binary Fission: a type of asexual reproduction used by prokaryotes (like bacteria)

  • One cell copies its DNA, then splits into two identical cells

• Prokaryotic DNA structure:

  • Prokaryotes (like bacteria) have one circular chromosome

  • No nucleus → DNA floats in the cytoplasm, usually in a region called the nucleoid 

Autosomal Dominant

• Trait shows up in every generation

• Affected parents can have unaffected children

• No carriers (you either have it or you don’t)

• Autosomal Recessive:

• Can skip generations

• Affected individuals may have unaffected parents

• Males and females affected equally

• Sex-linked Recessive:

• More common in males

• Females can be carriers

• Trait often passed from carrier mom to son

• Codominance:

• Both alleles are fully expressed 

• Example: Black + White cow = black and white spotted cow

Incomplete dominance

• Blending of traits

• Example: red flower + white flower = pink flower

• How can you tell if a trait is sex-linked? What are some key things you would notice?

• Mostly males affected

• No male carriers

• Affected sons often have carrier or unaffected moms

• Trait passed from mother to son, rarely from father to son

• Daughters need two affected X chromosomes to show the trait

• What factors may cause a mutation? 

• Radiation, chemicals, viruses, mistakes during DNA replication, spontanoeus changes in base sequences 

• Give some examples of beneficial mutations.

• Lactose intolerance, HIV resistance, sickle cell trait, extra copies of AMY1 gene