Bio 101 - Unit 2

What is the difference between passive and active transport?

Passive transport does not require energy and moves substances along the concentration gradient (high to low), while active transport requires energy (ATP) and moves substances against the concentration gradient (low to high).

What are 3 examples of passive transport?

Diffusion, osmosis, and facilitated diffusion.

What is meant by concentration gradient?

The difference in the concentration of a substance between two areas, typically across a membrane.

What are integral proteins?

Proteins embedded in the cell membrane that help transport molecules across the membrane.

What is meant by hypertonic, hypotonic, and isotonic?

Hypertonic: Higher solute concentration outside the cell, causing water to leave the cell.

Hypotonic: Lower solute concentration outside the cell, causing water to enter the cell.

Isotonic: Equal solute concentration inside and outside the cell, no net water movement.

What determines if a substance can move across the membrane (3 factors)?

Size, charge, and solubility in lipids.

What are the three types of gated channel proteins?

Voltage-gated, ligand-gated, and mechanically-gated channels.

What happens to a cell in a hypotonic solution?

The cell swells as water enters.

What happens to a cell in a hypertonic solution?

The cell shrinks as water leaves.

What happens to a cell in an isotonic solution?

The cell remains the same with no net water movement.

What is the difference between endocytosis and exocytosis?

Endocytosis brings materials into the cell by forming vesicles, while exocytosis releases materials out of the cell by fusing vesicles with the membrane.

What is the difference between pinocytosis and phagocytosis?

Pinocytosis is the ingestion of liquid (cell drinking), while phagocytosis is the ingestion of solid particles (cell eating).

What does "semipermeable" or "selectively permeable" mean?

It means the membrane allows only certain substances to pass through while blocking others.

Which 3 cell parts do ALL cells have?

Plasma membrane, cytoplasm, and DNA.

Describe a plasma membrane and its function.

The plasma membrane is a phospholipid bilayer that surrounds the cell and regulates what enters and exits the cell.

Describe a nucleus and its function.

The nucleus contains the cell's DNA and controls cell activities by regulating gene expression.

Describe a nucleolus and its function.

The nucleolus is inside the nucleus and is responsible for producing ribosomes.

Describe a vacuole and its function.

A vacuole stores water, nutrients, and waste products. In plant cells, it also helps maintain turgor pressure.

Describe a lysosome and its function.

Lysosomes contain digestive enzymes that break down waste materials and cellular debris.

Describe the Golgi bodies and their function.

The Golgi bodies modify, sort, and package proteins and lipids for transport to their final destinations.

Describe both smooth and rough ER and their functions.

Smooth ER: Synthesizes lipids and detoxifies chemicals.

Rough ER: Synthesizes proteins (has ribosomes attached).

Describe cytoplasm and its function.

Cytoplasm is the gel-like substance inside the cell that holds organelles in place and is the site of many cellular processes.

Describe a cell wall and its function.

The cell wall is a rigid layer outside the plasma membrane in plant cells that provides support and protection.

Describe a mitochondrion and its function.

Mitochondria are the powerhouse of the cell, producing ATP through cellular respiration.

Which type of cell would likely have more mitochondria—skin or muscle? Why?

Muscle cells, because they require more energy (ATP) for movement.

Describe ribosomes and their function.

Ribosomes are the site of protein synthesis, where they assemble amino acids into proteins.

What do microfilaments and microtubules do for the cell?

Microfilaments help with cell movement and shape, while microtubules help with cell division and organelle transport.

What are the two differences between cilia and flagella?

Cilia: Short, numerous, and move in a coordinated wave-like motion.

Flagella: Long, fewer in number, and move in a whip-like motion.

What are differences between plant cells, animal cells, and bacterial cells?

Plant cells: Have cell walls, chloroplasts, and large vacuoles.

Animal cells: Lack cell walls and chloroplasts, have small vacuoles.

Bacterial cells: Prokaryotic, no nucleus, have cell walls (not made of cellulose).

What is the difference between a prokaryotic cell and a eukaryotic cell?

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have both.

What is the difference between anabolic and catabolic metabolism?

Anabolic metabolism builds complex molecules from simpler ones (requires energy), while catabolic metabolism breaks down complex molecules into simpler ones (releases energy).

What is ATP? Does it get stored for long periods of time OR does it get used up quickly?

ATP (adenosine triphosphate) is the energy currency of the cell. It gets used up quickly and is not stored for long periods.

What are the reactants of aerobic respiration?

Glucose and oxygen.

What are the products of aerobic respiration?

Carbon dioxide, water, and ATP.

What are the products of lactic acid fermentation?

Lactic acid and ATP.

What are the products of alcoholic fermentation?

Ethanol, carbon dioxide, and ATP.

What is the difference between aerobic and anaerobic?

Aerobic processes require oxygen, while anaerobic processes do not.

What are the net ATP gains of aerobic vs anaerobic respiration?

Aerobic respiration produces ~36-38 ATP, while anaerobic respiration produces only 2 ATP.

What organelle(s) houses aerobic respiration?

Mitochondria

What organelle(s) houses photosynthesis?

Chloroplasts

Why do plants appear green?

Because chlorophyll, the pigment in chloroplasts, reflects green light.

What are the three steps to aerobic respiration? (name the 3 processes)

Glycolysis, the Krebs cycle, and the electron transport chain.

What are the reactants of photosynthesis?

Carbon dioxide, water, and sunlight.

What are the products of photosynthesis?

Glucose and oxygen.

What are the two processes associated with photosynthesis (2 steps)?

Light-dependent reactions and the Calvin cycle.

What process has occurred when your muscles burn after you go running? Why do they burn?

Lactic acid fermentation. The burn is due to the buildup of lactic acid in muscle cells when oxygen is low.

Be able to recognize the photosynthesis equation.

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

Be able to recognize the aerobic cellular respiration equation.

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP.

What is the difference between exergonic reactions and endergonic reactions?

Exergonic reactions release energy, while endergonic reactions require energy input.

What is glycolysis?

Glycolysis is the first step of cellular respiration, where glucose is broken down into two pyruvate molecules, producing 2 ATP and NADH.

How many ATP does it cost to do glycolysis? How many NET ATP are created at the end of glycolysis?

It costs 2 ATP to start glycolysis, and 4 ATP are produced, resulting in a net gain of 2 ATP.

Why do we state photosynthesis and respiration are interdependent?

Photosynthesis produces oxygen and glucose, which are used in respiration, while respiration produces carbon dioxide and water, which are used in photosynthesis.