71 Questions
What is the initial cell formed from the fusion of the ovum and spermatozoon called?
Zygote
What is the watery fluid containing organelles within a cell called?
Cytosol
What is the main function of the plasma membrane in a cell?
Regulate passage of substances into and out of the cell
What are the two layers that make up the structure of the plasma membrane?
Phospholipids
What is the function of membrane proteins in the cell membrane?
Act as receptors and enzymes
How do water-soluble ions cross the cell membrane?
Through channels
What type of transport involves substances moving down their concentration gradient?
Passive transport
What is the process called when waste materials are extruded through the plasma membrane?
Exocytosis
Which mechanism maintains unequal ion concentrations on either side of the plasma membrane?
Sodium-potassium pump
What type of transport involves moving substances up their concentration gradient using energy from ATP?
Active transport
Which type of substances can cross the membrane through channels?
Water-soluble ions
What is the selective permeability of the cell membrane responsible for?
Regulating the internal environment by controlling entry or exit of substances based on particle size
What does osmosis involve?
Passive movement of water across a semipermeable membrane towards equilibrium
What type of transport occurs when substances move down their concentration gradient?
Passive transport
What does facilitated diffusion use to move substances across the membrane?
Specialized protein carrier molecules
Which process involves moving substances up their concentration gradient using energy from ATP?
Active transport
Where is the principal concentration of potassium (K+)?
Inside the cell
Which organelle is responsible for synthesizing ATP through aerobic respiration?
Mitochondria
What is the main function of ribosomes in a cell?
Protein synthesis
Which process brings in fluid into the cell?
Pinocytosis
Where are enzymes located that digest fragments of organelles and large molecules inside the cell?
Lysosomes
Which organelle is involved in packaging proteins into membrane-bound vesicles for exocytosis?
Golgi apparatus
What is the main function of smooth endoplasmic reticulum?
Lipid synthesis
What is the function of cytoskeleton in a cell?
Guides movement of materials around the cell interior
What is the main function of microfilaments in a cell?
Providing mechanical support and shape to the cell
Which structure consists of a pair of centrioles and is important in cell division?
Centrosome
What are the microscopic hair-like projections that contain microtubules and move substances along the surface of some cells?
Cilia
What process results in two new, genetically identical daughter cells with 46 chromosomes each?
Mitosis
What is the period between two cell divisions known as?
Cell cycle
During which phase do the chromosomes replicate, forming two identical copies of DNA?
S phase
What is the main function of cilia in some cells?
Moving substances along the surface of cells
What is the process by which damaged, dead, and worn-out cells can be replaced by cell division?
Mitosis
What is the initial cell formed from the fusion of the ovum and spermatozoon called?
Haploid cell
Where is the principal concentration of potassium (K+)?
Nucleus
What type of substances can cross the membrane through channels?
Nucleic acids
What is the main function of smooth endoplasmic reticulum?
ATP production
What is the function of microtubules in a cell?
Provide mechanical support and guidance tracking for internal movement
What is the main function of centrosome in a cell?
Directing organisation of microtubules within the cell
Which structure contains tiny projections that greatly increase the surface area of cells, maximizing absorption of nutrients from the small intestine?
Microvilli
What is the process known as when ageing cells are programmed to 'self-destruct' and their components are removed by phagocytosis?
Apoptosis
What process results in two new, genetically identical daughter cells with 46 chromosomes each?
Mitosis
During which phase do the chromosomes replicate, forming two identical copies of DNA?
Synthesis of DNA (S phase)
What is the main function of cilia in some cells?
Moving substances along the surface of cells
What is the period between two cell divisions known as?
Cell cycle
Which type of cells have a resting phase called Go, even though they are usually highly active?
All types of cells
What organelle is involved in packaging proteins into membrane-bound vesicles for exocytosis?
Golgi apparatus
Where does meiosis take place?
In sex cells (ova and spermatozoa)
What type of transport allows substances to move down their concentration gradient?
Facilitated diffusion
Which process involves passive movement of water across a semipermeable membrane towards equilibrium?
Osmosis
Where is the principal concentration of potassium (K+)?
Inside the cell
What is the main function of microfilaments in a cell?
Cell movement
What is the process called when waste materials are extruded through the plasma membrane?
Exocytosis
What are membrane proteins involved in when using energy from ATP to move substances up their concentration gradient?
Active transport
How do water-soluble ions cross the cell membrane?
Through channels
What is the main function of the plasma membrane in a cell?
Regulation of internal environment
What type of proteins provide channels for electrolytes and non-lipid soluble substances in the cell membrane?
Membrane proteins
What is the main function of ribosomes in a cell?
Protein synthesis
What is the selective permeability of the cell membrane responsible for?
Regulating internal environment
What are the two layers that make up the structure of the plasma membrane?
Phospholipid bilayer and cholesterol layer
Which organelle is described as the 'powerhouse' of the cell?
Mitochondria
What type of transport occurs when substances move down their concentration gradient?
Facilitated diffusion
Where are enzymes located that digest fragments of organelles and large molecules inside the cell?
Lysosomes
What does osmosis involve?
Movement of water across a semipermeable membrane
What is the main function of smooth endoplasmic reticulum?
Lipid synthesis and detoxification
What process brings in fluid into the cell?
Pinocytosis
What is the function of cytoskeleton in a cell?
Facilitate movement of materials within the cell
Which type of substances can cross the membrane through channels?
Small molecules through simple diffusion
What is the main function of ribosomes in a cell?
Protein synthesis from amino acids using RNA as a template
What type of transport involves moving substances up their concentration gradient using energy from ATP?
Active transport
Where is the principal concentration of potassium (K+)?
Inside the cell
Which mechanism maintains unequal ion concentrations on either side of the plasma membrane?
Active transport
Study Notes
- Potassium (K+) is the principal intracellular cation with higher concentration inside the cell than outside. Sodium (Na+) is the principal extracellular cation, with higher concentration outside the cell than inside.
- Ions tend to diffuse down their concentration gradients, so cells maintain the gradients by constantly pumping out excess Na+ and taking in K+.
- Bulk transport of particles too large to cross cell membranes occurs through pinocytosis (cell-drinking) or phagocytosis (cell-eating).
- Pinocytosis brings in fluid while phagocytosis takes in larger particles and digests them with lysosomes.
- The cell contains various organelles, each with specialized functions and enclosed by their own membrane in the cytosol, including the nucleus, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and cytoskeleton.
- The nucleus, the largest organelle, contains the body's genetic material and is involved in metabolic activities. It has a nucleolus for ribosome synthesis and assembly.
- Mitochondria, described as the 'powerhouse' of the cell, are membranous structures responsible for the synthesis of ATP through aerobic respiration. They are found in high numbers in active cells.
- Ribosomes, tiny granules composed of RNA and protein, synthesize proteins from amino acids using RNA as a template. They are found in the cytoplasm and on the outer surface of the nuclear envelope and rough endoplasmic reticulum.
- Endoplasmic reticulum consists of membranous canals in the cytoplasm, with the rough type studded with ribosomes for protein synthesis. Smooth ER synthesizes lipids, steroid hormones, and participates in detoxification.
- The Golgi apparatus consists of stacks of folded membranous sacs and is present in all cells, but larger in those that synthesize and export proteins. It packages proteins into membrane-bound vesicles for exocytosis.
- Lysosomes are small membranous vesicles pinched off from the Golgi apparatus, containing enzymes that digest fragments of organelles and large molecules inside the cell. They are found in white blood cells for foreign material digestion.
- The cytoskeleton is an extensive network of protein fibers that provides internal support and guides the movement of materials around the cell interior.
(Note: Figures and references have been omitted as per the instructions.)
- Potassium (K+) is the principal intracellular cation with higher concentration inside the cell than outside. Sodium (Na+) is the principal extracellular cation, with higher concentration outside the cell than inside.
- Ions tend to diffuse down their concentration gradients, so cells maintain the gradients by constantly pumping out excess Na+ and taking in K+.
- Bulk transport of particles too large to cross cell membranes occurs through pinocytosis (cell-drinking) or phagocytosis (cell-eating).
- Pinocytosis brings in fluid while phagocytosis takes in larger particles and digests them with lysosomes.
- The cell contains various organelles, each with specialized functions and enclosed by their own membrane in the cytosol, including the nucleus, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and cytoskeleton.
- The nucleus, the largest organelle, contains the body's genetic material and is involved in metabolic activities. It has a nucleolus for ribosome synthesis and assembly.
- Mitochondria, described as the 'powerhouse' of the cell, are membranous structures responsible for the synthesis of ATP through aerobic respiration. They are found in high numbers in active cells.
- Ribosomes, tiny granules composed of RNA and protein, synthesize proteins from amino acids using RNA as a template. They are found in the cytoplasm and on the outer surface of the nuclear envelope and rough endoplasmic reticulum.
- Endoplasmic reticulum consists of membranous canals in the cytoplasm, with the rough type studded with ribosomes for protein synthesis. Smooth ER synthesizes lipids, steroid hormones, and participates in detoxification.
- The Golgi apparatus consists of stacks of folded membranous sacs and is present in all cells, but larger in those that synthesize and export proteins. It packages proteins into membrane-bound vesicles for exocytosis.
- Lysosomes are small membranous vesicles pinched off from the Golgi apparatus, containing enzymes that digest fragments of organelles and large molecules inside the cell. They are found in white blood cells for foreign material digestion.
- The cytoskeleton is an extensive network of protein fibers that provides internal support and guides the movement of materials around the cell interior.
(Note: Figures and references have been omitted as per the instructions.)
Test your knowledge on the movement of potassium and sodium ions across the cell membrane. Understand how cells maintain their concentration gradients and regulate the levels of these essential ions.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
