Biology 1 Exam Reviewer: From Cell Membranes to Cellular Respiration

Flashcards generated from the Biology 1 exam review guide covering cell membrane transport, homeostasis, disease, photosynthesis, and cellular respiration.

According to the review guide, what sequence of six cellular capabilities explains why life exists?

Life exists because cells can: 1. Control what enters and leaves, 2. Maintain internal stability, 3. Capture energy, 4. Store energy, 5. Release energy, and 6. Use energy.

What is the main function of the cell membrane?

The cell membrane separates the inside of the cell from the outside environment while allowing necessary exchanges to occur and maintaining control.

What is selective permeability?

Selective permeability is the property of the cell membrane that allows some substances to pass while others cannot.

How do passive transport and active transport differ regarding cellular energy expenditure?

Passive transport occurs without cellular energy expenditure (ATP), whereas active transport requires ATP to move substances against their natural direction.

What is diffusion?

Diffusion is the movement of molecules from high concentration to low concentration.

What is osmosis?

Osmosis is the diffusion of water across a selectively permeable membrane.

What is facilitated diffusion?

Facilitated diffusion is the movement of molecules from high concentration to low concentration across the membrane with the assistance of transport proteins, requiring no ATP.

What is active transport?

Active transport is the process of moving substances from low concentration to high concentration across a cell membrane, requiring ATP.

How do endocytosis and exocytosis differ in bulk transport?

Endocytosis is bulk transport where materials enter the cell, while exocytosis is bulk transport where materials leave the cell.

What is homeostasis?

Homeostasis is the maintenance of internal stability by constantly regulating conditions such as water, solutes, temperature, nutrients, and ion concentrations.

How is cancer characterized at the cellular level?

Cancer is uncontrolled cell division that occurs when normal cellular regulation fails and cells continue dividing even when they should stop.

What is the cellular problem in diabetes?

In diabetes, cells cannot effectively obtain or use glucose present in the bloodstream, leading to reduced energy availability and impaired cellular function.

How do genetic mutations lead to cellular disease?

Mutations alter the biological instructions contained in genes, which may produce abnormal proteins that cause disease.

Where do plants obtain their food?

Plants manufacture their own food through photosynthesis, not from soil, fertilizer, or water.

What role do chloroplasts play in plant cells?

Chloroplasts contain the cellular machinery needed to perform photosynthesis by capturing sunlight and converting it into usable energy.

What is the function of chlorophyll?

Chlorophyll is the pigment that absorbs light energy required for photosynthesis to occur.

What fundamental energy conversion takes place during photosynthesis?

Photosynthesis converts light energy into chemical energy, which becomes stored in glucose.

What are the primary products of the Light-Dependent Reactions stage of photosynthesis?

The Light-Dependent Reactions produce ATP, NADPH, and oxygen.

What materials does the Calvin Cycle use to manufacture glucose?

The Calvin Cycle uses ATP, NADPH, and carbon dioxide to manufacture glucose.

Why is ATP known as the energy currency of life?

ATP provides the immediately usable form of energy that cells require to power processes such as movement, thinking, growth, repair, active transport, and protein synthesis.

What is the significance of cristae in the mitochondrion?

Cristae are folds of the inner mitochondrial membrane that increase surface area, allowing for more ATP-producing machinery and greater efficiency.

How does the intermembrane space of a mitochondrion contribute to ATP generation?

The intermembrane space temporarily stores hydrogen ions ($H^+$) to build a proton gradient that drives ATP synthase to produce ATP.

Why does glycolysis occur in the cytoplasm?

Glycolysis is an ancient metabolic pathway that evolved before mitochondria existed, so it does not require mitochondria and occurs in the cytoplasm of both prokaryotic and eukaryotic cells.

What are the specific responsibilities of each stage of cellular respiration?

Glycolysis breaks down glucose; Acetyl CoA Formation prepares molecules for further breakdown; Citric Acid Cycle extracts additional energy; Electron Transport Chain transfers electrons and builds a proton gradient; Chemiosmosis uses that gradient to produce most ATP.

What is the overarching relationship between photosynthesis, cellular respiration, and life processes?

Photosynthesis captures and stores solar energy in glucose, cellular respiration releases that stored energy as ATP, and ATP powers essential life processes.