UIL Biology Topic 1 Flashcards

Front

What is the primary function of the cell membrane?

Back

Regulating entry and exit of substances

Answer explanation

The primary function of the cell membrane is regulating entry and exit of substances, allowing cells to maintain homeostasis by controlling what enters and leaves, unlike the other options which pertain to different cellular functions.

Front

Which macromolecule is the main component of cell membranes? Options: Carbohydrates, Proteins, Lipids, Nucleic acids, Vitamins

Back

Lipids

Answer explanation

Lipids are the main component of cell membranes, forming a bilayer that provides structure and regulates the movement of substances in and out of the cell. Other macromolecules play different roles but do not primarily compose membranes.

Front

Which type of transport does not require cellular energy? Options: Active transport, Endocytosis, Exocytosis, Facilitated diffusion, Phagocytosis

Back

Facilitated diffusion

Answer explanation

Facilitated diffusion is a passive transport process that allows substances to cross membranes without the use of cellular energy, unlike active transport, endocytosis, exocytosis, and phagocytosis, which all require energy.

Front

What is a carbohydrate's primary role?

Back

Energy supply

Answer explanation

Carbohydrates primarily serve as an energy supply for the body. They are broken down into glucose, which is used for immediate energy or stored for later use, making this option the best description of their primary role.

Front

Characteristic of enzymes:

• They are consumed in reactions
• They are lipids
• They increase activation energy
• They speed up chemical reactions
• They are nucleic acids

Back

They speed up chemical reactions

Answer explanation

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required. They are not consumed in the reactions, nor are they lipids or nucleic acids.

Front

Which structure within the cell is responsible for producing ATP?

Back

Mitochondria

Answer explanation

The mitochondria are known as the powerhouse of the cell, as they are responsible for producing ATP (adenosine triphosphate), the main energy currency of the cell, through cellular respiration.

Front

What is the role of ribosomes in the cell?

Back

Protein synthesis

Answer explanation

Ribosomes are essential for protein synthesis, as they translate messenger RNA (mRNA) into amino acid sequences, forming proteins. This process is crucial for cell function and growth, making 'Protein synthesis' the correct answer.

Front

Which molecule is known as the "energy currency" of the cell?

Back

ATP

Answer explanation

ATP, or adenosine triphosphate, is known as the "energy currency" of the cell because it stores and provides energy for various cellular processes, making it essential for life. Other options do not serve this primary energy role.

Front

Which of the following is a structural component of plant cell walls? Glycogen, Cellulose, Chitin, Starch, Keratin

Back

Cellulose

Answer explanation

Cellulose is a key structural component of plant cell walls, providing rigidity and strength. In contrast, glycogen and starch are energy storage polysaccharides, while chitin and keratin are found in fungi and animals, respectively.

Front

Which type of macromolecule is responsible for speeding up biochemical reactions?

Back

Proteins

Answer explanation

Proteins, specifically enzymes, are macromolecules that catalyze and speed up biochemical reactions by lowering the activation energy required for the reactions to occur.